Can you help me form an equation. Trying to help my friend for a job promotion.

Question

For every cup of sugar used, a certain recipe requires E eggs. Eggs cost D dollars and sugar costs F dollars. If John starts with X dollars, follows this recipe and uses C cups of sugar, how much money does he have left after buying all ingredients?

Answer 1

Hi Cheryl.  Phillip is certainly on the right track but unfortunately he flipped a sign when he factored C out of his last equation the correct equation should be:

 

Money Left = X - C(F + DE) 

Answer 2

I cup of sugar requires E eggs, so C cups of sugar requires C*E eggs.

 

Cost of sugar = $F*Number of Cups of Sugar = $F*C

 

Cost of Eggs = $D*Number of Eggs = $D*C*E

 

If John starts with $X, then:

 

Money Left = $X - Cost of Sugar - Cost of Eggs

 

Money Left = $X - $F*C - $D*C*E = $X -  C($F + $D*E)