\(5,=\dfrac{4x^2-8x-3x^2-6x+12x}{\left(x-2\right)\left(x+2\right)}=\dfrac{x\left(x-2\right)}{\left(x-2\right)\left(x+2\right)}=\dfrac{x}{x+2}\\ 6,=\dfrac{6+5x+15+x-3}{\left(x-3\right)\left(x+3\right)}=\dfrac{6\left(x+3\right)}{\left(x-3\right)\left(x+3\right)}=\dfrac{6}{x-3}\)
5: \(=\dfrac{4x^2-8x-3x^2-6x+12x}{\left(x-2\right)\left(x+2\right)}=\dfrac{x^2-2x}{\left(x-2\right)\left(x+2\right)}=\dfrac{x}{x+2}\)


