A store is selling two different types of cheese. One type sells for $3.75 a pound and a second
type sells for $4.55 a pound. How many pounds of the $3.75 cheese would the store need to mix
together with the $4.55 cheese to get a 45-pound mixture that sells for $4.05 a pound (round your
answer to the nearest pound?

  28 pounds

Step-by-step 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.

answer is the third choice:

3x^5+4x^4+x^3+2x^2-10x-7=0

step-by-step explanation: