Can someone help me plzzz

-6a - 48

4 + 36x

-30n + 42

18m + 20

To solve, set up a proportion

3.25 cups            x  cups
  = 
13 servings        28 servings

Now cross multiply

13x = 28 * 3.25

Simplify.

13x = 91

Divide both sides by 13

x = 7 cups

To check your answer, use proportions again, but change the left side to 4.5 cups over 18 servings, use the same steps,  if the answer is the same as above, then the answer is correct