Marissa wants to blend candy
selling for $1.80 per pound with
candy costing $1.20 per pound
to get a mixture that costs her
$1.40 per pound to make. she
wants to make 90 pounds of the
candy blend. how many pounds
of each type of candy should she
use?
explain in a formula, not just the !

Step-by-step explanation:

It generally works well to let a variable represent the quantity of the most-expensive contributor. Here, we can let x represent pounds of $1.80 candy.

Then 90-x will be pounds of $1.20 candy, and the total cost of the mix will be ...

  1.80x + 1.20(90-x)

We want that to be the same value as 90 pounds of $1.40 per pound mix, so the equation is ...

  1.80x + 1.20(90 -x) = 1.40(90)

This can be simplified and solved like any two-step linear equation.

  0.60x + 108 = 126 . . . . . simplify

  0.60x = 18 . . . . . . . . . . . .subtract 108

  x = 30 . . . . . . . . . . . . . . . divide by 0.60. This is pounds of $1.80 candy

  90-x = 60 . . . . . pounds of $1.20 candy

30 pounds of candy priced at $1.80 per pound, and 60 pounds of candy priced at $1.20 per pound should be used to make a mix that costs $1.40 per pound.