2mn/4m²-9与2m-3/2m+3 要全过程的,最简公分母是什么?2mn/4m²-9与2m-3/2m+3最简公分母是什么？
问题描述：
2mn/4m²-9与2m-3/2m+3 要全过程的,最简公分母是什么?
2mn/4m²-9与2m-3/2m+3
最简公分母是什么？
答
最简公分母是4m²-9，（2m+3）*（2m-3）=4m²-9，即右边等于（2m-3）²/4m²-9
答
（2m+3)(2m-3)
答
2mn/(4m²-9)与(2m-3)/(2m+3)
2mn/(2m+3)(2m-3)与(2m-3)/(2m+3)
2mn/(2m+3)(2m-3)与[(2m-3)^2]/[(2m+3)(2m-3)]
2mn/(4m²-9)与(4m²-6m+9)/(4m²-9)
答
把2m-3/2m+3上下同时乘以4m-3，就行啦啊
答
①2mn/4m^2-9=2mn/[(2m+3)(2m-3)]
②2m-3/2m+3=(2m-3)(2m-3)/[(2m+3)(2m-3)]=(2m-3)²/[(2m+3)(2m-3)]
③2mn/4m²-9与2m-3/2m+3=2mn-(2m-3)²/[(2m+3)(2m-3)]
最简公分母是[(2m+3)(2m-3)]