Question

Kelli and Karl each have a job. Kelli earns $20 an hour. She also receives a $100 weekly bonus. 

Answer 1

Equation for Kelli's earning = 20x + 100
Equation for Karl's earning = 25x + 50

Now, 20x +100 = 25x +50
25x-20x = 100-50
5x = 50
x = 10

So, your answer is 10 hours.

Hope this helps!

Answer 2

20h+100=25h+50
20h+50=25h
50=5h
10=h
They must work 10 hours a week to earn the same amount.

Hope this helps :)