91Ó°ÊÓ

Subtract:

$\frac{6x^2-x+20}{x^2-81}-\frac{5x^2+11x-7}{x^2-81}$

Subtract:

$\frac{y^2-5y}{y^2-4}-\frac{6y-6}{4-y^2}$

(a) Multiply $\frac{7}{4}·\frac{9}{10}$and explain all your steps.

(b) Multiply $\frac{n}{n-3}·\frac{9}{n+3}$and explain all your steps.

(c) Evaluate your answer to part (b) when $n=7$. Did you get the same answer you got in part (a)? Why or why not?

Simplify:$\frac{x^2-x-2}{x^2-3x+2}$

Subtract:

$\frac{2n^2+8n-1}{n^2-1}-\frac{n^2-7n-1}{1-n^2}$

(a) Find the LCD for the expressions $\frac{3x}{x^2-3x+10},\frac{5}{x^2+3x+2}$

(b) rewrite them as equivalent rational expression

with the lowest common denominator.

Add:

$\frac{2}{x-2}+\frac{5}{x+3}$

Add:

$\frac{4}{m+3}+\frac{3}{m+4}$

Add:

$\frac{1}{m^2-m-2}+\frac{5m}{m^2+3m+2}$

Add:

$\frac{2n}{n^2-3n-10}+\frac{6}{n^2+5n+6}$