# How do you solve the equation for y: x^2+17x+72=0?

Jul 8, 2015

Solve $y = {x}^{2} + 17 x + 72 = 0$

#### Explanation:

$y = {x}^{2} + 17 x + 72 = 0.$
I use the new Transforming Method (Google, Yahoo Search)
Find 2 numbers knowing sum (17) and product (72). Both real roots are negative (Rule of Signs).

Factor pairs of 72 -> ...(-4, -18)(-6, -12)(-8, -9). This sum is -17 = -b.

Then, the 2 real roots are:$- 8 \mathmr{and} - 9.$