Answer:
x =2 y= 8
Step-by-step explanation:
Answer:

Hence, option C is true.
Step-by-step explanation:
Given the expression

Solving for 'm'

Flip the equation

Expanding by applying the distributive law: 

Add (-1)/2 × kn to both sides

simplify

Divide both sides by k/2


Therefore,

Hence, option C is true.
Let the number of hour it took them to have completed the same number of problems be x, then
15 + 10x = 9 + 12x
12x - 10x = 15 - 9
2x = 6
x = 6/2 = 3
After 3 hours, they must have completed the same number of homeworks.
I believe the answer is 3 3/4.