通分1/2m^2+3m与(2m+5)/4m^2-9
问题描述：
通分1/2m^2+3m与(2m+5)/4m^2-9
答
公分母：m(2m+3)(2m-3)
1/(2m²+3m)=(2m+3)/[m(2m+3)(2m-3)]
(2m+5)/(4m²-9)=(2m²+5m)/[m(2m+3)(2m-3)].