### Home > PC > Chapter 7 > Lesson 7.3.3 > Problem7-125

7-125.

Use substitution to show that the statements below are true.

1. $−3$ and $2$ are roots of the equation $x^{2} + x − 6 = 0$.

Substitute $−3$ first for $x$. Simplify.
Substitute $2$ next for $x$. Simplify.

2. $−1 + \sqrt { 7 }$ is a root of the equation $x^{2} + 2x − 6 = 0$.

$(-1 + \sqrt 7)^2 + 2(-1 + \sqrt 7) -6 =0$

$(-1 + \sqrt 7)(-1 + \sqrt 7) + 2(-1 + \sqrt 7) -6 =0$