Question 1021994

A metallurgist has one alloy containing 28% aluminum and another containing 64% aluminum.  How many pounds of each alloy must he use to make 49 pounds of a third alloy containing 45% aluminum?  (Round to two decimal places if necessary.)
In the equation it has it equaled out as .28x+.64y=22.05
How do they get the 22.05?
<pre>.28x + .64y = .45(49) --------> .28x + .64y = 22.05. As you can see, .45(49) = 22.05.