Question 794799
A number = x
The sum of a number and its square is 156
x + x^2 = 156
x^2 + x - 156 = 0
(x - 12)(x + 13) = 0
x + 13 = 0
x = -13 (no answer as x <0)
x - 12 = 0
x = 12
The number is 12.
Hope this helps.
:-)