This document provides an algebra lesson on writing and solving equations. It begins by defining algebraic expressions and equations. An example shows writing an expression for "three more than four times a number." Steps are given for solving equations algebraically, including an example of solving the equation "Three more than two times a number is 4" for the number. The document concludes with class activities involving solving simple equations and writing an equation for a word problem.

1. ALGEBRA
GRADE : 8
UNIT : 1
Initials & Surname: T.G Mabodla
student no. 216044938
Link: https://www.slideshare.net/ThapeloMabodla

2. LESSON OBJECTIVES
 At the end of the lesson learners should be able to:
 Read, write and solve equations.

3. Writingexpressionsandequations
We use a letter such as “x” or “n” to represent a
number
We can write an algebraic expression to represent
a word statement for example, a “number plus five”
can be written as “ n+5
When we write an algebraic expression as equal to a
number or another expression , we have an
equation. For example: n+5=8

4. Example 1
Write an algebraic expression for this statement:
 Three more than four times a number
Solution: let “x” represent the number.
then four times a number is 4x.
three more than 4x is:
4x+3 or 3+4x

5. Solving equation algebraically
 Let us look at how to solve equations algebraically.
EXAMPLE
 Three more than two times a number is 4. What is the number?
 STEP1: write an equation>> let the number be n.
then two times a number is 2n
three more than two times a
number is: 3 + 2n
the equation is: 3 + 2n = 4

6. continue…..
 Step 2: Solve the Equation
3 + 2n = 4
3 + 2n – 3 = 4 – 3 to isolate 2n, subtract 3 from each side
2n = 1
2n/2 = 1/2 divide each side by 2.
n = ½

7. continue…
 Step 3: verify the solution
 substitute n = 1/2 into 3 + 2n = 4
LHS = 3 + 2n RHS = 4
= 3 + 2(1/2)
= 3 + 1
= 4
THEREFORE: n = 1/2 is correct because RHS = LHS.

8. NOWYOU TRY THISONE !
Work with a partner. Solve this problem
 My Mother’s age is 4 more than 2 times my Brother’s age.
 My mother is 46 years old.
 How Old is my Brother??

9. conclusion

10. class activity
1.Solve each equation.
a) 2x = 3 b) 3x = 2 c) 5x = 12
2. Solve each equation then verify the solution.
a) 5 + 2m = 6 b) 7 = 1 + 3n
3. Write, then solve an equation to solve this question.
Ten more than three times a number is 25. what is the number??

11. Reference list
Arohl , L. (2014). Learning materials / modules in MATHEMATICS Grade 7 Quarter 3. Available from slide share at
https://www.slideshare.net/lhoralight/k-to-12-grade-7-learning-material-in-mathematics-quarter-3
CoreAces. (2018). Solving Linear Equations - GRADE 8 MATHEMATICS. Available from slideshare at
https://www.slideshare.net/CoreAces/solving-linear-equations-grade-8-mathematics?qid=c6f6d404-e882-452d-b6b8-
668a826ca58b&v=&b=&from_search=2
CoreAces. (2018). Rational Expressions- Grade 8 Mathematics. Available from slideshare at
https://www.slideshare.net/CoreAces/rational-expressions-100249468
Eary, S. (2009). Solving Algebraic Equations. Grand Valley State University. Available from slideshare at
https://www.slideshare.net/earys/solving-algebraic-equations-1570338?qid=4137e2e6-67c4-40ff-a2ae-
4df6145559a0&v=&b=&from_search=1. Published in: Education, Technology
Granada, N. (2013) K to 12 - Grade 8 Math Learners Module Quarter 2. Available from slide share at
https://www.slideshare.net/wroachATriagroup2013/assessment-model-2-prealgebra-grade-8
Published in: Technology, Education