anh chị giúp em với ạ gấp lắm roii

1, $\frac{9x+2+15x-2}{4x^2y}$ 

= $\frac{24x}{4x^2y}$ 

= $\frac{6}{xy}$ 

2,$\frac{x+2-x}{x-1}$ 

=$\frac{2}{x-1}$ 

3,$\frac{5x+7-2x+5}{3xy}$ 

= $\frac{3x+12}{3xy}$ 

= $\frac{x+4}{xy}$ 

4,$\frac{4x+9}{(x+2)(4x+9)}$- $\frac{1}{(x+2)(4x+9)}$ 

=$\frac{4x+9-1}{(x+2)(4x+9)}$ 

=$\frac{4x+8}{(x+2)(4x+9)}$ 

=$\frac{4(x+2)}{(x+2)(4x+9)}$ 

=$\frac{4}{4x+9}$ 

5,$\frac{a(a+3)}{(a+3)(a-3)}$ - $\frac{3(a-3)}{(a-3)(a+3)}$ 

=$\frac{a^2+3a-3a+9}{(a+3)(a-3)}$ 

=$\frac{a^2+9}{a^2-9}$ 

6,$\frac{6}{2x(x+2)}$ + $\frac{x}{2x(x+2)}$ 

=$\frac{6+x}{2x(x+2)}$ 

7, $\frac{11x}{2x-3}$ + $\frac{x-18}{2x-3}$ 

= $\frac{11x+x-18}{2x-3}$ 

=$\frac{12x-18}{2x-3}$ 

=$\frac{6(2x-3)}{2x-3}$ 

=6

8,$\frac{x(x-y)}{(x+y)(x-y)}$- $\frac{y(x+y)}{(x+y)(x-y)}$ 

= $\frac{x^2-xy-xy-y^2}{(x-y)(x+y)}$ 

= $\frac{x^2-y^2}{(x+y)(x-y)}$ 

=$\frac{(x-y)(x+y)}{(x+y)(x-y)}$ 

=1