Question 174207
let the number of pounds of soybean and cornmeal be s and c respectively
we know there are 360 pounds altogether 
:
s+c=360................eq 1
.18s+.09c=.11(360).....eq 2
:
lets rewrite eq 1 to s=360-c and take that value and plug it into eq 2
:
.18(360-c)+.09c=39.6
:
64.8-.18c+.09c=39.6
:
-.09c=-25.5
:
{{{highlight(c=280)}}}pounds of cornmeal
:
{{{highlight(s=360-c=360-280=80)}}}pounds of soybean meal

This makes alot of sense because the cornmeal is 9% protein which is much closer to the final mixture of 11% protein that the soybean which is 18%. So it definitely fits that we use alot more of the cormeal mix to reach our 11% protein goal