Question 287048
The Outdoor Club held a car wash to raise money. They washed cars for $5 each and vans for $7 each. They washed 45 vehicles and earned $243. How many of each type of vehicle did they wash? 
So far I put, 
Let X represent cars
Let Y represent vans 
I can't think of the two equations. Help! 

1.) X + Y = 45
2.) 5*X + 7*Y = 243

From 1.) you know that Y = 45 - X.

Substitute 45 - X for Y in equation 2.):

5*X + 7*(45-X)= 243

Solve the equation above for X then calculate  Y = 45 - X.