Answer
$\displaystyle \frac{1}{x+1}$
Work Step by Step
Distribute $-1$ over the brackets,
$= \displaystyle \frac{3x}{(x+1)^{2}}-\frac{5x+1}{(x+1)^{2}}+\frac{3x+2}{(x+1)^{2}}$
... To add/subtract rational expressions with the same denominator,
add/subtract numerators and place the sum/difference over the common denominator.
$= \displaystyle \frac{3x-(5x+1)+3x+2}{(x+1)^{2}}$
$= \displaystyle \frac{3x-5x-1+3x+2}{(x+1)^{2}}$
$= \displaystyle \frac{(x+1)}{(x+1)(x+1)}$
... common factors cancel,
= $\displaystyle \frac{1}{x+1}$
