a △ b means (7-a)*(3+b). Find c if

Question

3 △ 1=5 △ c Please help. Ms.Sue possible to answer??

Answer 1

Just plug in the numbers.

3△5 = (7-3)(3+5) = 32
5△c = (7-5)(3+c) = 6+2c

so,

32 = 6+2c
c = 13

Answer 2

Thank You