help with this problem please

Question

can someone solve this problem please?
Nancy and Adriana use a metal alloy that is 16% copper to make jewelry. How many ounces of 
an 11% alloy must be mixe
d with a 24% alloy to form 130 
ounces of the desired alloy?

Answer 1

It is a Algebra 1 real-world application problem.

24% alloy to form 130 ounces of the desired alloy means there are total of 20.80 ounces of copper.

Setup a system of algebraic equations with 2 unknowns
x=amount of 11% metal alloy
y=amount of 24% metal alloy
11%x=0.11x=amount of Copper from 11% metal alloy
24%y=0.24y=amount of Copper from 24% metal alloy

Equation 1:Total amount of metal alloy after mix:       x+y=130
Equation 2:Total amount of Copper after mix:            0.11x+0.24y=20.80

»0.11x+0.11y=130*0.11=14.3
Subtract Equation 1 from Equation 2
»0.24y-0.11y=0.13y=20.80-14.3=6.5
»0.13y=65
Solve for y
»y=50
Plugin y=50 to Equation one
»x+50=130
»x=80

The answer is 80 ounces of an 11% alloy.