[tex]\it a)\ =\dfrac{5(x-1)}{2x(x-1)}=\dfrac{5}{2x}\\ \\ \\ b)=\dfrac{(4x-1)(4x+1)}{4x(4x-1)}=\dfrac{4x+1}{4x}\\ \\ \\ c)\ =\dfrac{(x-3)(x-4)}{(x-3)(x+3)}=\dfrac{x-4}{x+3}\\ \\ \\ d)\ =\dfrac{(4x+1-2x+3)(4x+1+2x-3)}{4(x+2)^2}=\dfrac{(2x+4)(6x-2)}{4(x+2)^2}=\dfrac{4(x+2)(3x-1)}{4(x+2)^2}=\\ \\ \\ =\dfrac{3x-1}{x+2}[/tex]
