The red bus company charges $150 plus $72 per hour to rent a bus. the blue bus company charges $240 plus $54 per hour.
a. for what number of hours would the companies charge the same?

b. what would the charge be for that number of hours?

X is the amount of hours that the companies would charge the same,
and y is the charge for that number of hours.

We will do a system of two, two-equations two-variables.

150 + 72x = y        E1
240 + 54x = y        E2

We'll work it out by elimination, removing y and obtain x.

E1 - E2 =>
(150 - 240) + (72 - 54)x = (y-y)
-90 + 18x = 0
18x = 90
x = 5

A. For 5 hours.

Now to get y, lets use any of the two equations to get y, lets use E2

240 + 54*5 = y
y = 240 + 270
y = 510

B. It would cost 510$

(tell me, did you get it? its better when you actually learn how to do it; I hope I helped you clarify. Also dont rely solely on other people doing your stuff =P, but gl anyways)

Red Bus Company 

Price = 150 + 72h

Blue Bus Company

Price = 240 + 54h

Try to solve now and let me know if you need more help 

1. 8 or -82. 14 or -143. -11, -3, 0, 7, 10