Plug it into each equation and see if both sides are equal:
A. 36 = (2+4)^2 -> 36 = 36 works
B. 36 = 7(2)^2 +2 -> 36 = 30 doesn't work
C. 36 = (3(2))^2 -> 36 = 36 works
D. 36 = 2(2)^2 -> 36 = 8 doesn't work
The answer is -10 and -13. when added they equal -23 and when you switch the symbol of the 10 and make the equation 10-13 you get -3. hope this helped.