Equations: the unknown on both sides

The Maths Habit

  1. Solve 5(x + 2) = 35

    x = 5

  2. Solve 4(x − 3) = 18

    x = 7.5

  3. Solve 2(3x + 4) = 2

    x = −1

Left: 5 bags and 2 marbles.
Right: 3 bags and 12 marbles.
Bags hold the same. It balances.
What could you take off both sides?

3 bags, or 2 marbles: 5 in a bag

Simplify

  1. 5x − 2x

    3x

  2. 7x − x

    6x

  3. 4x − 9x

    −5x

  4. 3x − 3x

    0

Which side has fewer x?

2x + 11 = 6x + 3 The left

Solve 5x + 2 = 3x + 12

− 3x both sides2x + 2 = 12− 2 both sides2x = 10÷ 2 both sidesx = 5
Answerx = 5

Solve 6x + 4 = 2x + 16

− 2x both sides4x + 4 = 16− 4 both sides4x = 12÷ 4 both sidesx = 3
Answerx = 3

Solve 5x + 2 = 3x + 12

− 3x both sides2x + 2 = 12− 2 both sides2x = 10÷ 2 both sidesx = 5
Answerx = 5

Solve 7x + 1 = 4x + 13

− 4x both sides3x + 1 = 13− 1 both sides3x = 12÷ 3 both sidesx = 4
Answerx = 4

Solve 5x + 2 = 3x + 12

− 3x both sides2x + 2 = 12− 2 both sides2x = 10÷ 2 both sidesx = 5
Answerx = 5

Solve 6x + 3 = 2x + 27

− 2x both sides4x + 3 = 27− 3 both sides4x = 24÷ 4 both sidesx = 6
Answerx = 6

Solve 5x + 2 = 3x + 12

− 3x both sides2x + 2 = 12− 2 both sides2x = 10÷ 2 both sidesx = 5
Answerx = 5

Solve 2x + 19 = 5x + 4

− 2x both sides19 = 3x + 4− 4 both sides15 = 3x÷ 3 both sidesx = 5
Answerx = 5

Solve 5x + 2 = 3x + 12

− 3x both sides2x + 2 = 12− 2 both sides2x = 10÷ 2 both sidesx = 5
Answerx = 5

Solve 4x + 9 = x + 15

− x both sides3x + 9 = 15− 9 both sides3x = 6÷ 3 both sidesx = 2
Answerx = 2

Equations: the unknown on both sides worksheet, page 1

Answer sheet

  1. I think of a number. Five times my number add 2 is the same as three times my number add 16. What is my number?

    7

  2. Solve 3(x + 2) = x + 14

    x = 4

  1. Solve 7x + 4 = 3x + 24

    x = 5

  2. Solve 4x + 25 = 9x + 5

    x = 4

  3. Solve 5(x − 1) = 2x + 13

    x = 6
Exit tickets to print