a=14% protein in soybean b=7% protein in cornmeal

how many pounds mixed together to get 280lb mixture that is 9% protein

a= ____lbs soybean

b= ____lbs cornmeal

Thank you from the bottom of my heart,

2 answers

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Looks like a classical algebra problem to me.

280lbs=S+C weight equation
280*.09=.14S+.07C protein equation

How to solve?
I would multiply the top equation by .07, then subtract one equation from the other.