Real life systems of linear equations

Question

Jackie wants to make a mixture of nuts to sell in her Store consisting of hazelnuts and cashews. Hazelnuts cost $6.50 Per pound and cashews cost $4.50 per pound. If Jackie wants 60 pounds total of mixture and the cost to be $5.10 per pound, how many pounds of each will she need?

Answer 1

h + c = 60 ----> h = 60 - c

6.5h + 4.5c = 5.1(60)

Substitute!

6.5(60 - c) + 4.5c = 306

390 - 6.5c + 4.5c = 306

-2c = -84

c = 42

h = 60 - 42

h = 18