### Home > PC3 > Chapter 1 > Lesson 1.1.6 > Problem1-55

1-55.

Are the following pairs of expressions equivalent? Explain how you know using at least two different methods.

1. $\frac { x ^ { 2 } - 1 } { x ^ { 2 } + 1 }$ and $-1$

1. $\frac { 3 x + 2 } { x - 1 }$ and $3+\frac{5}{x-1}$

Try substituting values such as $x=2$$3$, 4 etc.