Candy is selling at $6.00 per pound will be mixed with candy selling at $9.00 per pound. how many pounds of the more expensive candy are needed to produce a 15 pound mixture that sells for $7.00 per pound

Use a table

Cost*amount=value

add collumes and multiply rows

C x A = V

6 y = 6y

9 15-y = 9 (15-y)

7 15 = 105

6y+9 (15-y) = 105

6y+135-9y=105

-3y+135=105

subtract 135

-3y=-30

divide - 3

y=10

15-y=15-10=5

10 pounds of $6 mixture

5 pounds of $9 mixture

check

10*6=60

5*9=45

60+45=105

7*15=105

105=105

check

10 pounds $6

5 pounds $9