Question 168860
NOT FAMILIAR WITH A 2 EQUATION SYSTEM TO SOLVE THESE TYPES OF PROBLEMS. 
HERE'S THE STANDARD METHOD.
.16X+.09(350-X)=.12*350
.16X+31.5-.09X=42
.07X=42-31.5
.07X=10.5
X=10.5/.07
X=150 LB. OF SOYBEANS ARE USED.
350-150=200 LB. OF CORN MEAL IS USED.
PROOF:
.16*150+.09*200=42
24+18=42
42=42