Question

How do you solve `x^{2} + 2x = 15`?

Answer 1

3 and -5

Explanation:

`y = x^2 + 2x - 15 = 0`
Find 2 numbers knowing sum (-b = -2) and product (c = -15).
Factor pairs of (c = -15) --> (-3, 5)(3, -5). This sum is (-2 = -b).
The 2 real roots are: 3 and -5