Answer:
Step-by-step explanation:
let x = how many joe sold
let 4x = how many abe sold
900 = x + 4x
900 = 5x
180 = x
joe sold 180
and abe sold 4x
4(180) = 720
hat means Abe sold 720 trucks
finally, let's check our answer to make sure the total is 900
180 + 720 = 900
our answer is right