A car wash costs 7 for a car 12 for trucks if 370 is collected for 40 vehicles how many cars and trucks were washed?

A car wash costs 7 for a car 12 for trucks if 370 is collected for 40 vehicles how many cars and trucks were washed?
22 cars and 18 trucks

Let x = the number of cars. Since you know a total of 40 vehicles were washed, 40 minus the number of cars (x) is the number of trucks.
7x +12(40-x) = 370
7x + 480 - 12x = 370
-5x = -110
x = 22

40 - 22 = 18

To check:
22 * 7 + 18 * 12
154 + 216
370