Question

Work out the value of x.

Answer 1

x = 20

Explanation:

4x+5x = 180° (sum of int angles)

9x = 180°

x = 20°

Hence, x = 20.

Answer 2

`\huge\boxed{x=20}`

Useful Information:

Co-interior angles add to 180°

Explanation:

The first step is to add 4x to 5x, which gives you 9x. This is because co-interior angles add up to 180, so 4x+5x=180. Co-interior angles can be spotted by their C shape.

To work out the value of x you would need to divide 180 by 9, which gives you 20°. This is because 9x is equal to 180. This means that x is equal to 180 divided by 9.

1) Add 4x to 5x.

`4x+5x=9x`

2) Divide 180 by 9.

`(180)/(9)=20`