so let 3,680=y and you have to solve 3,680=360x+1000. first subtract the 1000 from both sides the equation is now 2,680=360x next divide 360 to both sides x would equal 7.444444......since he only has 3,680 to spend if it is a decimal you need to round down so the total amount of months he can lease the car is 7 months