Answer: the cost for each pound of chocolate chips is $1.25 and each pound of walnuts is $2.5
Explanation:
Let x represent the the cost for each pound of chocolate chip.
Let y represent the the cost for each pound of walnut.
2 pounds of chocolate chips and 3 pounds of walnuts cost a total of $10. This means that
2x + 3y = 10- - - - - - - - - - - - - 1
For 4 pounds of chocolate chips and 8 pounds of walnuts, the total cost is $25. This means that
4x + 8y = 25- - - - - - - - - - - - - 2
Multiplying equation 1 by 2 and equation 2 by 1, it becomes
4x + 6y = 20
4x + 8y = 25
Subtracting, it becomes
- 2y = - 5
y = - 5/ - 2
y = 2.5
Substituting y = 2.5 into equation 1, it becomes
2x + 3 × 2.5 = 10
2x + 7.5 = 10
2x = 10 - 7.5 = 2.5
x = 2.5/2
x = 1.25