通分 (2-x)/(4-2x)与(2x)/(x^2-4)

问题描述:

通分 (2-x)/(4-2x)与(2x)/(x^2-4)

答:
(2-x)/(4-2x)
=(x-2)/(2x-4)
=(x-2)(x+2)/[2(x-2)(x+2)]
=(x^2-4)/[2(x^2-4)]
(2x)/(x^2-4)
=4x/[2(x^2-4)]