Im so confused every time i answer this question i get a decimal

Question

Solve this application problem using a system of equations: Amy and Penny use a metal alloy that is 20% copper to make jewelry. How many ounces of an alloy that is 19% copper must be mixed with an alloy that is 23% copper to form 86 ounces of the desired alloy?

Answer 1

Let x = amount of 19% alloy and y = amount of 23% alloy

Then we have the system of equations:

x + y = 86

0.19x + 0.23y = 0.20(86)

-0.19x - 0.19y = -16.34

0.19x + 0.23y = 17.2

0.04y = 0.86

So, y = 21.5 oz and x = 86 - y = 64.5 oz