The sum of a number and its square is 1406. What is the number?
38
39
37
29
Explanation:
Let the number be x.
Then, x + $x^2$ = 1406
=> $x^2$ + x-1406 = 0
=> x = -1 + $-\sqrt(1-4 \times 1406)$/2
=> x = -1 + -75/2
=> x = -38 or x=37.