Question 5342
Let x = the basic fee
let y = the additional amount charged

basic fee + number of days*charge = total cost

x+5y=45
x+2y=24

subtract the second equation from the first:
3y=21
divide both sides by 3
y=$7

put y back into either equation and solve for x:
x+5(7)=45
x+35=45
x=10

verify with other equation:
x+2y=24
10+2(7)=24
10+14=24, so this is correct.

To find out how much it costs for 8 days,
basic charge + 8days(cost per day)=total
10+8(7)= total
10+56=66
$66 for 7 day rental