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Soybean meal is 16% protein: cornmeal is 8% protein. How many pounds of each should be mixed together in order to get 320-lb. mixture that is 14% protein?
2 answers
Let x = amount of soybean meal used
y = amount of cormeal used
x + y = 320
.16x + .08y = .15(x + y) = .15(320) = 48
.16x + .08y = 48
That's two equation and two unknowns:
x + y = 320
.16x + .08y = 48
Multiply the first equation by .08:
.08x + .08y = 25.6
.16x + .08y = 48
Subtract the first equation from the second equation:
.16x - .08x + .08y - .08y = 48 = 25.6
.08x = 22.4
Divide by .08:
x = 280
x + y = 320
280 + y = 320
y = 40
Use 280 lbs of soybean meal and 40 lbs of cornmeal.
y = amount of cormeal used
x + y = 320
.16x + .08y = .15(x + y) = .15(320) = 48
.16x + .08y = 48
That's two equation and two unknowns:
x + y = 320
.16x + .08y = 48
Multiply the first equation by .08:
.08x + .08y = 25.6
.16x + .08y = 48
Subtract the first equation from the second equation:
.16x - .08x + .08y - .08y = 48 = 25.6
.08x = 22.4
Divide by .08:
x = 280
x + y = 320
280 + y = 320
y = 40
Use 280 lbs of soybean meal and 40 lbs of cornmeal.