Christine earns $12 for each hour of yard work. How many hours in all will it take Christine to earn $24?

2 hours

Step-by-step explanation:

If she works 2 hours it would be 24

2 hours

Step-by-step explanation:

hourly rate * number hours = total earned

12 * h = 24

Divide each side by 12

12h/12 = 24/12

h =2

x = -3

y = -18

step-by-step explanation:

to solve by substitution, substitute one variable and solve for the other. then substitute again to find the remaining variable.

x-1/3(3x-9) = -3 since y=3x-9 substittute y.

x-1/3(3x-9)=-3

x + x +3 = -3

2x+3=-3

2x+3-3= -3-3

2x=-6

x=-3

substitute again into y=3x-9

y=3(-3)-9

y=-9-9

y=-18