Respuesta :

PHDFlopper
Set up a system of equations:
x=number of cars washed
y=number of trucks washed

x+y=122
3x+5y=510

Solve using elimination:
Multiply the first equation by -3:
-3x-3y=-366
3x+5y=510

Add the two equations together:
2y=144
y=72

The answer is 72 trucks
72 trucks is the answer to the problem.