If you don’t mind...who were you? as in your name?
(x+5)*7=133
7x+35=133
7x=98
x=98/7
x=14
Food A has fewer calories per serving.
I found this by taking the first food (A) and dividing 150 by 3. This gave me 50, which I added onto 150 to give me my 4/4 of a serving (200 calories).
With food B, I did the same process. I took 250/2 and added that to the original amount to get the final third of the serving, which resulted in food B being 375 calories.
Answer: -8 and -4
This is something you do through trial and error. Making a list or a table like shown below might help.
The midpoint is C, (-0.5,0.5)
Find the middle between the x and y coordinates and that is the midpoint