Question

soybean meal is 18% protein; cornmeal is 9% protein . How many pounds of each should be mixed together in order to get 360lb mixture thats 10% protein

Answer 1

We need to equations, the first one deals with pounds

s + c = 360

Answer 2

The second equation deals with protein

soybean protein + cornmeal protein = mixture protein

.18s + .09c = .10(s + c)

or

.18s + .09c = .10(360)

Answer 3

Do you know how to solve

s + c = 360
.18s + .09c = .10(360)

after multiplying the second equation by 10

s + c = 360
18s + 9c = 3600

Would you use elimination or substitution?

Answer 4

substitution I think maybe im wrong

Answer 5

I got the 3600 in my math but i got lost after that

Answer 6

\[.18x+.09(360-x)=36\]solve for x

Answer 7

probably easier to get rid of annoying decimals and solve
\[18x+9(360-x)=3600\]

Answer 8

yes i got rid of the decimals also

Answer 9

\[18x+3240-9x=3600\]
\[9x=3600-3240\]
\[9x=360\]
\[x=360\div9=40\]

Answer 10

so now would i do the same but put 18 in the place of 9