Question

A truck can be rented from company A for $100 a day plus 0.30 per mile. Company B charges $80 a day plus 0.70 per mile to rent the same truck. How many miles must be driven to make the rental cost for Company A a better deal than Company B?

Answer 1

@ConDawg @reemii @tkhunny @texaschic101

Answer 2

turn into lieanr equations and set equal to eachoter

Answer 3

\[100+0.30x=80+0.70x\]

Answer 4

Solve for x

Answer 5

We could graph two equations, one for each rental company, and compare where A is below B. A bit of a shortcut would be to set the two equal to each other, and find the amount of miles where they cost the same -

100+.3x = 80 + .7x
20 + .3x = .7x
20 = .4x
50 = x

So, because B charges more per mile, after 50 miles, B costs more money, so A is a better deal.

Answer 6

\[20+0.30x=0.70x\]

Answer 7

\[20=0.4x\]

Answer 8

\[x=50\]

Answer 9

x = number of miles
100 + .30x = 80 + .70x
100 - 80 = .70x - .30x
20 = .40x
20/.40 = x
50 = x
Okay....they are the same at 50 mph. For company A to be a better deal, you would have to drive 51 miles....lets check
Company A. 100 + .30(x) = 100 + .30(51) = 100 + 15.30 = 115.30
Company B 80 + .70(51) = 80 + 35.70 = 115.70
ANSWER : 51or more miles must be driven for Company A to be a better deal