Question

将分式 1/(x-2) 1/(3x+6) 3/(x^3-4x) 通分后,他们分别变为__________________

Answer 1

3x+6=3(x+2)

x^3-4x=x(x+2)(x-2)

所以最简公分母是3x(x+2)(x-2)

所以

1/(x-2)=3x(x+2)/[3x(x+2)(x-2)]

1/(3x+6)=x(x-2)/[3x(x+2)(x-2)]

3/(x^3-4x)=9/[3x(x+2)(x-2)]