A merchant wishes to blend 200 pounds of coffee worth $3.20 a pound from two mixtures: one at $3.00 a pound and the other at $3.25 a pound. How many pounds of each mixture should he use?

X pounds of $3

y pounds of $3.25

x+y = 200

300x + 325y = 320*200

300x + 325y = 64000

x+y = 200

300x + 325y = 64000

Solve by eliminating

Multiply top one w/-300

-300y = 60000

325y=64000

25y = 4000

y = 160 then

x + 160 = 200

x = 40

So the mixture has;

40 pounds of $3 coffee

160 pounds of $3.25 coffee