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Appetizers and Lessons for Mathematics and Reason
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20 pages in French: Algèbre  
 Définition d'une variable
  
La raison basée sur les  règles et modelés

www.whyslopes.com >  Solving Linear Equation  >   Section Introduction     Next ]


How to Solve Linear Equations 

Students: The steps below to develop linear equation solving skills and to improve fraction skills and sense below come from the pen of a mathematician with 15 years of  experience in preparing students for further study. Skill in arithmetic with fractions is a must for algebra. \

Teachers and Tutors:  See the guide below.

 Steps to improve fraction and algebra skills

Step 1. It easier for the beginning student of mathematics to understand a problem of finding x  when  x is the length x of a line segment 

x


than it is find x when x stands for a number,  the solution (a number)  of an equation.  Solving Linear Equations with stick diagrams  employ  letters as lengths of line segments - the easy case - to help people learn the second case.  

(i) x + 20 = 29 WS
(ii) 2x + 6 = 24 WS
(iii) 3x + 10 = 32 WS
(iv) 5a + 16 = 3a+ 24 WS
(v)  (½)x + 8 = 24½ WS
(vi)  (¾)a + 16 = (¼)a+ 24 WS
(vii) (¾)q + 17 = 32 WS
(viii) 13 =[2/3]x +7 twice WS
(5/6)q + 8+(5/6) = 14 + (2/3) WS
Proper Use of Equal Sign

The above links lead to about 30 examples.  

 

Step 2. Solving Equations without stick diagrams    

Step 3Solving Equations in essentially one unknown. Seeing how to solve systems of simultaneous equations in essentially one unknown provides an easier route for tackling word problem which lead to solving one equation in one unknown.

Step 4Gaussian Elimination,  substitution method for systems of Equations in two unknowns/ The substitution method met in solving equations in essentially one unknown sets the stage for rewriting linear equations in essentially one unknown form.  That provide a simple way to introduce Linear Systems and one form of Gaussian Elimination.

Step 5. Two More Forms of Gaussian Elimination 

  • Comparison
  • Equation (or Row) Addition and Subtraction, as is or after multiplication.

Learn all three forms, and watch for situations in which one requires less work than the others. That may make the harder.  

Step 6. Gaussian Elimination Method for Larger Systems. The Gaussian elimination method extends to linear equations in more unknowns. 

Step 7. Assign solving linear equation in Chapter 15 of Volume 2, Three Skills for Algebra, as optional readings. 

Skill Development Guide:  

This section shares ideas and methods for developing algebraic skills first with and then without stick diagrams.  Fractional operations on stick diagrams will develop or reinforce fraction sense.  Tell students that exact arithmetic with whole numbers and fractions is a must for advanced mathematics and in that  a must for algebra. These ends, values and methods  for work and study may help.  Some able students may have greater patience for being taught if you put them into a group of in-class tutors, and talk about common errors and mistakes they need to watch for and correct, and if you knowing how to develop skills in this topic of Solving Linear equation provides a richer and stronger command of the topic.  This guide is continued in the blue column. 

Junior High School Topic (Remedial for Senior High School or College Maths)

Solving Linear Equations  ax+b = cx+ d with stick diagrams - where x or another letter denotes an unknown length - one that can be drawn.  Solution follow from fractional operations on line segments may introduce students to solving linear equations without stick diagrams (Next topic)  and also reinforce fraction sense and skills. Adopt the  three column format to provide an example of how following a format allows steps to be done and recorded, one at a time, one after another in an observable manner.   That give a model and a standard for showing work. 

Solving linear equations.  Solving Linear ax+b = cx+ d without  stick diagrams where the letter x may denote an unknown number, one that cannot be seen, rather an unknown length, one that can be seen. The format used and advocated  here also appears in .purplemath.com  coverage of the same topic .  The format show students how to do steps in an observable and verifiable or correctable manner. A second reason for the format is its resemblance to a format use later in (a) solving systems of equations in two unknowns; and in  (b) the statement of rules for manipulating equations - obtaining equivalent ones.  

Enrichment:  Chapter 15 of Volume 2 begins with  examples of a repetitive kind  and  goes further. It introduces the algebraic (literal) solution of equations in a step-by-step manner.  U may like it. 

Solving  Simultaneous Equations in essentially one unknown.  Many  elementary  word problems in junior high school require students to find and express all quantities in terms of  one unknown - the essential unknown - in setting up a linear equation in that unknown . But the linear relations in such problems may more readily be written as simultaneous equations in two or more unknowns,  simultaneous equations likely to easily recognized as having essentially one unknown.  The foregoing kinds of word problems can be made simpler by showing students how to solve simultaneous equations in essentially one unknonw. That is 

 Solving  Simultaneous Equations in the other easy case, the  "triangular or diagonal" system case, where no elimination is needed, may serve as a prequel to solving simultaneous equations by elimination.  

Senior High School Topic:  Gaussian Elimination for Simultaneous  Linear Equations

(i) )  substitution method for systems of Equations in two unknowns  The substitution method met in solving equations in essentially one unknown sets the stage for rewriting linear equations in essentially one unknown form or in triangular form.   

(ii) Two More Forms of Gaussian Elimination   (a) comparison and (b) Equation (or Row) Addition,  Subtraction and Multiplication.  The comparison method leads to one equation in one unknown to solve..  The Addition etc method leads to a triangular system to solve. (Examples or further examples are given  in the Making Triangular Section of  Chapter 15 of Volume 2, Three Skills for Algebra . The chapter ends with an example of triangularization of a system of equations in 3 unknowns via the addition etc method.

 

Solving Linear
Equations
(Feb 14, 2005)
with & then without stick diagrams plus   solving word problems; and solving systems: -  essentially one unknown, essentially triangular & general

A. Letters and Lengths
B. Solving Linear Eq'ns - WS
C. Solving Linear Eq'ns - No Sticks
D. Almost One
E Substitution Methods
F. Two More Methods
G. Larger Systems
H.  Exercises to Try


Read them in order

(i) x + 20 = 29 WS
(ii) 2x + 6 = 24 WS
(iii) 3x + 10 = 32 WS
(iv) 5a + 16 = 3a+ 24 WS
(v)  (½)x + 8 = 24½ WS
(vi)  (¾)a + 16 = (¼)a+ 24 WS
(vii) (¾)q + 17 = 32 WS
(viii) 13 =[2/3]x +7 twice WS
(5/6)q + 8+(5/6) = 14 + (2/3) WS
Proper Use of Equal Sign



 

For Senior High School  & Calculus Students

  <| (o)   (o)   |> 
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 -/[]\- 
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Words  to clearly introduce algebra and variables have been missing in course design. For people who cannot do algebra, 
the missing words may explain or ease their difficulties.  Volume 2 ,Three Skills for Algebra,  in Chapters 8 to 14 & 18 etc, puts words before symbols to providing the missing words in a way that enrich the comprehension of all.  Those words form the middle part of a algebra (and logic) lessons aimed at helping or improving all of  high school mathematics and also calculus course design & delivery. 

For Avid Readers in School & Out - Online Books 
   1.  Elements of Reason. 1996 
1A. Pattern Based Reason  1995 
1B. Math Curriculum Notes 1996 
2. Three Skills for Algebra  1995 
3.
Why Slopes & More.Math 1995
Tour their 
forewords.   

Calculus Prep or Help: See Volumes 2 & 3, and this bigger Calculus Guide.  If your  calculus   questions is not answered here, submit it. Over time, that may complete the site development of calculus. 

For Parents: Speaking Skills, Reading & Writing Preparing for Scienceends, values and methods for work and study,  parent- friendly maths skill development booklets for ages 4-14.

Mostly For High School

Intro to Solving Linear Equations
 
- a different paths for junior and even senior high school students. Question for Tutors: When do you use and when you skip the stick diagram method here?

Fraction Skills,  thought-based  development, Ages 10 to 14 may need a tutor.  Students who have to understand in order to do may like the development in all or part. 

For Senior High School Mathematics & Calculus

5
wordy Logic Chapters
4 curious Algebra Chapters
Words before & besides symbols. A Key Algebra forward & backwards Chapter   
 

First Calculus Preview (1st intro)
Four Calculus Chapters  (2nd intro)
Intro to Complex Numbers (long)
Intro to Mathematical Induction (romantic & wordy at first)

Tutors & Instructors: These lessons introduce skills differently Would you recommend them? 

More Topics 

1. Decimal Arithmetic  Reference!
2. Integers - Intro to Signed No.s

3.  Fractions - fully explained.
4.  Fractions  with Units  
5.   Number Theory
6.    Solving Linear Equations  
Formulas for- & backwards -  
8.  Proportionality, Back- & For-wards.   
9. Logic Chapters:   
10.  Euclidean-Geometry  
11.  Slopes & Equations of Straight Lines.  (Take I. See take II below)
12.  Why Study Slopes
13. Maps, Plans,  Similarity & Trig,  
  (Take II included here)
14.  Quadratics: Starter lessons
15.  Polynomials: Starter lessons 
16 Why Factor Polynomials:  
17   Functions - Forwards & Backwards.  
18.  Exponents, Radicals & logs.  
19
Complex Numbers before trig (new advance/ starter lesson)
20.  DC Electric Circuits Etc 
21.
Real  Analysis 
22. The Olde Complex No, Trig
& Vector Section.
23. More Calculus Stuff
- written after Volumes 2 and 3.

Level I Material: New Stuff
Time and Date Matters
Level I Arithmetic. 
Money Matters
Measurement Matters
Matters of Chance (Risk Control)
Logic Chapters (leave what's not clear in Level I to Level II)
Using/Making Maps and Plans.
(A variant of
Maps, Plans,  Similarity & Trig,  to appear here).

For Instructors
-
Education Essays   (opinions, possibilities, references) 
- Free Advice and Directions for teaching primary & high school maths will be given in online meeting place with voice & whiteboard.   
- Math & Logic  How-TOs 
1. Arithmetic
2. Algebra
3. More Algebra
4.  Beginner Geometry
5.  More Geometry
6. Calculus 
7. Show Work or Logic 
These may be too dense for students.

Offering ideas to change education makes this site different.  Nothing ventured, nothing gained.  Site material is mathematically  correct, and where not, please report errors. The two level program POMME in the site entrance implies multiple paths for instruction. Supporting those paths in turn implies a clear destination  for site development and perhaps a new name.


 


www.whyslopes.com > Solving Linear Equations   >   Section Introduction     Next ]


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Try to see what  trucks, cars, buses or bicycles are coming, so that you may step out of their way.  Put safety first. .

Support for Technical Mathematics from Number Theory to Calculus Prep

A. More Arithmetic a must for algebra etc D. Logic In Mathematics G. Algebra with Take Home Value I. Vectors & Functions
Decimal Lesson - Reference  
Counting & Addition
   (8 lessons)
Comparison to Subtraction
  (9 lessons)
Multiplication
( 11 lessons)
Long Division  (12 lessons)
Decimals and Primes (8 lessons)
-Primes & Composites 
-Primes Factorization
-Greatest Common Divisors & Multiples.
 
-Prime Factorization Aids 
(Learn how to find factors quickly)
-Prime Factorization Examples
 
-Counting & Generating. Factors

-Divisibility Rules and Remainders for Division by 2, 3, 5, 9 and 11.
Integers (12 lessons) Intro to Signed Numbers
Fractions (< 20 lessons)  Essential Skills & Concepts 
Ratios & Fractions (3 lessons):  Similarities & Differences
  
Units in calculations
Fractions  with Units
B.  Basic Algebra
Solving Linear Equations  
- in one unknown. Intro  with stick diagrams?
the normal way
 & with good nttn.
(the nttn that reappears in Gaussian Elimination. |
-in more unknowns: simultaneous equations essentially one unknown. the let algebra do the work view of  word problems.
  - still in more unknowns:  Gaussian Elimination via substitution, by equality or comparison, by operations on equations
C. More Algebra
Words before symbols: See if U like the lengthy chapters 8 to 12 in Volume 2, Three Skills for Algebra  
What is a Variable.  The answer here  is a simple prequel to the modern mathematics viewpoint.
First, every rule & pattern U meet in math, logic & science will be used forwards and backwards.  Get a head start with this theme by reading  Chapter 14 in Three Skills for AlgebraSecond, in the study of Proportionality Relations (3 dense lessons here) finding the proportionality constant gives an initial  backward  use of the proportionality formula.
 Talking about words before symbols and the forward and backward use of formulas gives words to make algebra simpler & clearer.  
If you can not read or write precisely, you will have difficulty in following instructions.  One wordy remedy  is given by chapters 2 to 5  in Three Skills for AlgebraWhere does Logic or a geometric model for reason Appear in Mathematics? The answer lies in  Euclidean-Geometry    In North America, Euclidean Geometry disappeared from high school mathematics as it was too hard. The light treatment here is a possible remedy.
E.  More Geometry
The Pythagorean Theorem. Chapter 17 from  in Three Skills for Algebra uses algebra and geometry   to show why the  Pythagorean equation  for right triangles holds. Its forward and backward use  is common exercise..  At a more theoretical level, the Pythagorean theorem leads the discovery that not all lengths can be  fractional multiples of a unit length. That geometrically implies a  need for and even existence of irrational numbers.
Analytic Geometry:
Common Practices with  Maps and Plans drawn to scale  give coordinate-dependent base  for senior high school development of similarity, trig, vectors and straight lines.   
Complex Numbers: This lesson on
Complex Numbers  draws on Euclidean and Analytic geometry. Sbortcuts simplifiy  trig identities, the cosine law; and   trig formulas for 2D dot- and cross-products. 

F. Logarithms, Exponentials,
Roots & Powers

Logarithms, exponentials, rational and real powers for secondary students. This  complete Operational Viewpoint. (Sufficient for the precalculus forward and backward use of compound growth and decay formulas in biology, physics, chemistry,  personal finance, and calculus. To learn more, if you study calculus,  see chapter 19 of Volume 3, Why Slopes and More.Math

In Volume 2, Three Skills for Algebra, chapters
  1. Geometric Sums Etc,
  2. Notation For Sums,
  3. Personal Money Maths and
  4. Some Finite Mathematics
identify methods useful in money computations, methods needed for calculus. Your teachers or other writer may present the same ideas with greater clarity and detail - A site to do.

H. Polynomial & Quadratics

Analytic Geometry:   -  Slopes and Lines - Take 1.   Take 2 appears in site section Maps and Plans.   Two views are better than one.  I may combine them later.  -In my school days, slopes appeared year after year.   This Why  Slopes calculus preview on graphs of functions y = f(x) explains why.  Enjoy.
Quadratics and Polynomials: Operations on Polynomials:
Meet a light and ultraquick geometric introduction to  multiplication, addition and subtraction of polynomials. Then see how the foregoing combine to permit long division of polynomials.    Compare Fractions  with Units. Enrichment: A Plus:  The Geometric introduction here gives or is almost identical to a justification for column methods in decimal arithmetic. 
Geometric Derivation of the Quadratic Formula  The account here gives a starter lesson for the more algebraically harder geometric-free derivation. If you study physics, chemistry or trigonometry, you will need to know about quadratics, their factorization and the quadratic formula.
Technical Value: The study of polynomials  high school mathematics has technical value as part of the senior high school mathematics preparation for calculus.  This simple account of Why Factor Polynomials   (Chapters 2 to 6 in Volume 3 .Why.Slopes.&.More.Math.) will give a context for the study of polynomials,  their factorization, and sign analysis of functions, all in a way that should improve your algebraic thinking and reasoning skills. 
Vectors in the Plane (2 simple lessons)
- Navigation with vectors or arrows
- Sum of Motions
- more lessons to be added later.
Operations on movement or vectors along the line and in the plane have value in mathematics in defining and implying the properties of real and complex numbers before the assumption of those properties as axioms.  Vectors and their properties appear in physics, its mathematical description and formulation. 
Functions - Forwards & Backwards.  Here is a full technical reference (24 lessons) for use in a calculus or precalculus course as needed. In it, the set viewpoint of functions expression of modern pure mathematics.  comes from the set-based codification and
In the mathematics education reforms of the 1960s in North America, primary and secondary school mathematics were expressed in terms of sets. That expression has now retreated from primary and secondary school texts. But it still lingers on, and can be very useful, a source of clarity and precision, in the situations where it should be retained: Counting with the aid of sets and functions; the description of functions; the high school account of probability theory; and in the discussion or illustration of ideas in logic. 

J. Pre-Calculus Skill Check

Arithmetic Skill Check.  In the calculus courses I taught 1983-89, too many students had weak skills in arithmetic. I would give and carefully correct these exercises to tell students what they needed to review and master.  
-  All the skills and concepts in 
Chapters 1 to 24 or Volume 2, Three Skills for Algebra: Look for those you do not understand and fill the gaps. Do so quickly while balancing this advice with  your other duties.  Good luck.

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