Question 1154197

A chemical company makes two brands of antifreeze. The first brand is 45% pure antifreeze, and the second brand is 85%  pure antifreeze. In order to obtain 40 gallons of a mixture that contains 75%  pure antifreeze, how many gallons of each brand of antifreeze must be used?
<pre>.45F + .85(40 - F) = .75(40)
.45F + 34 - .85F = 30
- .4F = - 4
F, or {{{highlight_green(matrix(1,11, Amount, of, "45%", antifreeze, to, mix, "=", (- 4)/(- .4), "=", 10, gallons))}}}
{{{highlight_green(matrix(1,11, Amount, of, "85%", antifreeze, to, mix, "=", 40 - 10, "=", 30, gallons))}}}