77. Mixture You wish to make a one-pound blend of two types of coffee, Kona and Java. The Kona costs $8 per pound and the Java costs $5 per pound. The blend will sell for $7 per pound. a. Let & and j denote the amounts (in pounds) of Kona and Java, respectively, that go Into making a one-pound blend. One equation that must be satisfied by k and / is k + J =1 Both k and j must be between 0 and 1. Why? b. Using the variables k and j, write an equation that expresses the fact that the total cost of one pound of the blend will be $7. c. Solve the system of equations from parts (a) and (b), and interpret your solution