3 friends bought an equal number of fruits each from the same store. Alan bought 5 oranges and some apples, and paid $7.80. Bob bought 11 oranges and some apples, and paid $9. Chris bought only apples. How much did Chris pay for his apples?
They all bought the same number of fruits
Let 'x' be the number d = price of orange a = price of apple
5d + ( x-5)a = 7.80 <====== Multiply by -2.2 and add to the second equation ( this is to cancel ou the 'd')
11d + (x-11)a = 9.00
-2.2(x-5)a + (x-11)a = -2.2(7.80)(9.00)
simplifying this results in xa = 6.80 this is the amount Chris spent on 'x' apples