so the salsa uses 65% of tomatoes, and it just so happen for that is 5.2 cups.
let's say the salsa is "x" cups, namely 100%, and we know that 5.2 cups is 65%, thus

Answer:
8.43
Step-by-step explanation:
8 + 10 + 10 + 10 + 6 + 7 + 8 = 59
59/7 = 8.43 (or keep as improper fraction)
Transpose the y into the left part of the equation and the 20 should be on the right
y= -20x