a: \(=\dfrac{2x\left(x+1\right)}{3\left(x+1\right)}=\dfrac{2x}{3}\)
b: \(=\dfrac{\left(x+2\right)\left(x-1\right)}{\left(x-1\right)\left(x+1\right)}=\dfrac{x+2}{x+1}\)
c: \(=\dfrac{x\left(x+4\right)}{x\left(x-6\right)}=\dfrac{x+4}{x-6}\)
d: \(=\dfrac{\left(x+2\right)^2}{x\left(x+2\right)}=\dfrac{x+2}{x}\)
e: \(=\dfrac{5b\left(3a+b\right)}{\left(3a+b\right)\left(3a-b\right)}=\dfrac{5b}{3a-b}\)
f: \(=\dfrac{\left(x-y\right)^2}{3\left(x-y\right)}=\dfrac{x-y}{3}\)
g: \(=\dfrac{-x\left(x+2\right)}{\left(x+2\right)\left(x-2\right)}=\dfrac{-x}{x-2}\)
h: \(=\dfrac{x\left(x-2\right)\left(x+2\right)}{x+2}=x\left(x-2\right)\)