Question 1017708
x=20%
24-x=70%
.20x+.70(24-x)=0.50*24=12 gallons of pure acid.
.20x+16.8-.70x=12
-0.50x=-4.8
x=9.6 gallons of 20%=1.92 gallons pure acid.
24-x=14.4 gallons of 70%=10.08 gallons pure acid.
Sum is 12 gallons pure acid, checks.