Problem is attached in the picture.

Question

anonymous · Answer

attachment

anonymous · Answer

Oh a mixture prob. a?

anonymous · Answer

Yeah it is.

anonymous · Answer

that's what I got..

anonymous · Answer

missed the decimal at the beginning. let me try again.
$$.18x+.09(360-x)=.11\times 360$$ finally

anonymous · Answer

so whatever you get for x with that equation is the amount of soy in LBS

anonymous · Answer

and 360 - the amount of soy, is the amount of corn

anonymous · Answer

reasoning as follows. if x is the amount of 18 % mixture then it has 18% of x protein, this is .18x
and since the total is 360 the 9% mixture must be 360-x, and it has 9% protein so it contributes .09(360-x) protein.  you end up with 11$ of 360 which is .11*360

anonymous · Answer

now we solve.  get rid of the stupid decimal first
$$18x+9(360-x)=11\times 360$$
$$18x+3240-9x=3960$$
$$9x=720$$
$$x=80$$