## 4. Solving equation

Solve the following equations to find the value of x

a. 4x = 20

x = 5

b. 3x – 7 = 8

3x = 8 + 7 ( it is important to get the order 8 + 7 right and not 7 + 8: even the answer is same, the answer is NOT be the same when subtracting, see the example below)

3x = 15

x = 5

c. 8(x + 12) = 100

8x + 96 = 100 ………………Expand the brackets

8x = 100 – 96………………. (subtract 96 on both sides (remember balancing equations?)

x = 4/8 (Why divide 8? In order to find the value of x, you must divide LHS and RHS by 8)

x = 1/2 (or 0.5)

Solve the following to find the value of y

a. y/3 = 9

y = 27 ………….multiply 3 x 9 (now, this is important as you can use this to solve complex equations that have a divisor)

b. 2y/5 = 4

2y = 20………. ( 20 = 5 x 4)

y = 10

c. 2y + 3 / 2 = 5

2y + 3 = 10………. ( 10 = 2 x 5)

2y = 10 – 3 ………..(subtracting 3 on both sides of the equation)

2y = 7

y = 7/2

y = 3.5