Answer:
28 pounds
Explanation:
Let x represent the amount of $3.75 cheese needed for the mix. Then the total cost of the mix is ...
3.75x +4.55(45 -x) = 4.05(45)
-0.80x = 45(4.05 -4.55) = -0.50(45) . . . . . simplify, subtract 4.55(45)
x = (5/8)(45) = 28.125 . . . . . . . . . . . . . .divide by -0.80
To the nearest pound, 28 pounds of $3.75 cheese would be needed in the mix.