Question

Matthew currently has enough money to buy 45 toy cars. If the cost of each car was 10 cents less, Matthew could buy 5 more cars. How much money does Matthew have to spend on toy cars?

Answer 1

let (y) be the amount of money Matthew has. Let (x) be the price of each car:

y = 45(x)

Now if the cars cost 10cents less, than Matthew can buy 5 more:

y = (45+5)(x - 0.10)

y = 50(x - 0.10)

y = 50x - 5

Now you have two equations, we'll plug in 50x - 5 for (y) in the first equation:

y = 45x

50x - 5 = 45x

5x - 5 = 0

5x = 5

x = 1

So the price of each car is 1 dollar, meaning that Matthew has 45 dollars, since he could originally buy 45 cars