Deandra is doing her math homework. Out of 24 problems total, she completed the first 12 problems in 1 hour and the last 12 problems in 3 hours. What is the unit rate for all 24 problems? 4 problems per hour
6 problems per hour
8 problems per hour
12 problems per hour

30

step-by-step explanation:

times by times

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

use distributive property on all like terms and change your signs if you have a double negative or if you have positive/negative