### Home > PC3 > Chapter 6 > Lesson 6.1.3 > Problem6-56

6-56.

Solve each of the following equations. Use $u$-substitution to make the process easier.

1. $(x^2+x−2)^2-2(x^2+x-2)=8$

• Let $u=x^2+x-2$.

1. $\frac { 12 } { \sqrt { x ^ { 2 } + 5 } } + \sqrt { x ^ { 2 } + 5 } = 7$

Let $u=\sqrt{x^{2}+5}$.