Question 207578
 Car rental agency A will rent a compact car for $40 per day and an additional
 charge of $0.20 per mile. Car rental agency B will charge only $0.16 per mile
 but charges $51 per day. If Adam wanted to rent a car for four days, how many
 miles would Adam have to drive to make car rental agency B a better bargain -
:
Let x = no. of miles driven for Agency B a better deal than A agency
:
Agency A 4-day cost greater than Agency B 4-day cost
.20x + 4(40) > .16x + 4(51)
:
.20x + 160 > .16x + 204
:
.20x - .16x > 204 - 160
:
.04x > 44
x > {{{44/.04}}}
x > 1100 mi
:
We can say that when the mileage exceeds 1100, B is cheaper than A
:
Let's say he drives 1101 mi
A: .20(1101) + 160 = 380.20
B: .16(1101) + 204 = 380.16; 4 cents cheaper
;
:
Answer to the question,"why does the variable not go in the denominator?"
You have to multiply the number of miles by the cost per mile, Right?
:
A mileage cost: 1100 * .20 = $220
:
"/" just per means "per" in this case, not divide.