Answer:
0.5 gallons
Step-by-step explanation:
Let x represent the amount of orange juice (in gallons) Gayle must add to the mix. Then the total amount of orange in the mix is ...
0.25(2) +x = 0.40(2+x)
0.50 +x = 0.80 +0.40x . . . . eliminate parentheses
0.60x = 0.30 . . . . . . . . . . . . subtract 0.50+0.40x
x = 0.5 . . . . . . . . . . . . . . . . . divide by 0.60
Gayle should add 0.5 gallons of orange juice to make a 40% solution.
