Question

480:x-40=64:8
(4•x-20)+720=900​

Answer 1

1)

480:(x-40) = 64:8

480 * 8 = 64 * (x - 40)

3840 = 64x - 2560

3840 + 2560 = 64x

6400 = 64x

6400/64 = x

x = 100

2)

(4x - 20) + 720 = 900

4x - 20 + 720 = 900

4x + 700 = 900

4x = 900 - 700

4x = 200

x = 200/4

x = 50