Question 58158
x = amount of 20% copper
y = amount of 70% copper
*Remember: x = 50 - y
(0.2x + 0.7y)/50 = 0.5
0.2x + 0.7y = 25
0.2(50 - y) + 0.7y = 25
10 - 0.2y + 0.7y = 25
0.5y = 15
y = 30
x = 50 - y = 50 - 30 = 20
30 pounds of 70% copper
20 pounds of 20% copper