Answer: You will need 3.5lbs of the cheaper candy
and 5 lbs of the expensive candy.
Step-by-step explanation:
Let x represent the number of pounds of the cheaper candy that you would need.
Let y represent the number of pounds of the expensive candy that you would need.
You would like to have 8.5 lbs of a candy mixture. It means that
x + y = 8.5
You have one type of candy that sells for $1.70/lb and another type of candy that sells for $3.40/lb. The candy mixture would sell for $2.70/lb. It means that the total cost of the mixture would be 8.5 × 2.7 = $22.95. The expression would be
1.7x + 3.4y = 22.95- - - - - - - - - - - 1
Substituting x = 8.5 - y into equation 1, it becomes
1.7(8.5 - y) + 3.4y = 22.95
14.45 - 1.7y + 3.4y = 22.95
- 1.7y + 3.4y = 22.95 - 14.45
1.7y = 8.5
y = 8.5/1.7
y = 5
x = 8.5 - y = 8.5 - 5
x = 3.5
