Answer:
5 hours
Step-by-step explanation:
Set up an equation where y=total cost and x= hours
y=7x+15
Substitute 50 for y, the total cost, and solve for x, the total hours
50=7x+15, Subtract 15 from both sides
35=7x, Divide both sides by 7 to get x alone
x=5
Answer:
a=15
Step-by-step explanation:

Hope it helps
Answer:
k=8
Step-by-step explanation:
divide both sides by 11 to get nine
then subtract 1 from both sides to get
8
Answer:
3,700
299,677,710
9,780
Step-by-step explanation: