X

x

(x+7)(x-8) = 0

Either -7 or +8 will satisfy the requirements for your number.

Check

(-7)

8

^{2}- 56 = xx

^{2}- x - 56 = 0(x+7)(x-8) = 0

Either -7 or +8 will satisfy the requirements for your number.

Check

(-7)

^{2}- 56 = 49 - 56 = -78

^{2}- 56 = 64 - 56 = 8