Question 158688
X= the number of gallons of a 20% acid solution. The equation for the above problem is  .20X + (.30x6)=.22(X + 6)   I converted the % to decimals. ie 20%=.2 just divide by 100. therefore .20X + 1.8 = .22X + 1.32   Subtract .20x from .22 and you get .02X   Subtract 1.32 from 1.8 and get 0.48. Now you can solve for X  0.48=.02X   X=24 gallons. To check the result plug in X and see if you get the same answer on both sides!