Simply this number 15min :3hours​

1 min : 12 min

Step-by-step explanation:

To simplify the given ratio, convert both to the same unit of time.

1 hour = 60 minutes

3 hours = 3 x 60 minutes

             = 180 minutes

So that,

15 min : 3 hours = 15 min : 180 min

divide through by 15 to have;

15 min : 180 min = 1 min : 12 min

Thus the simplified form of the number give is 1 min : 12 min.

x = -4

step-by-step explanation:

- 20 - 4(x + 3) = 4x

=> -20 - 4x - 12 = 4x

=> - 32 -4x = 4x

=> -32 = 4x + 4x

=> - 32 = 8x

=> -32/8 = x

=> -4 = x