通分4m²-9分之2mn与2m+3分之2m-3

m的3次方+2m的平方+m分之m-1=(m-1)/m（m²+2m+1）=（m-1）/m（m+1）²=（m-1）²/m（m+1）²（m-1）m的平方-1分之2=2

“liljw0924”：二个数的分母分别为4m²-9和2m+34m²-9=（2m）²-3²=（2m+3）×（2m-3）它们的公分母是（2m+3）×（2m-3）通

答：mn/(m+n)=2分子分母同除以mn得：1/(1/n+1/m)=21/m+1/n=1/2(3m-5mn+3n)/(-m+3mn-n)分子分母同除以mn得：=(3/n-5+3/m)/(-1/n+3

最简公分母是（1＋m）（1－m）²m²－2m＋1分之m＋1=（1－m）²（1＋m）分之（m＋1）（1＋m）=（1＋m）（1－m）²分之（m＋1）²1－

4m²-9=(2m+3)(2m-3)所以最简公分母就是4m²-9所以(2m-3)/(2m+3)=(2m-3)²/(4m²-9)

解最简公分母2(x+y)²,∴(x-y)/(2x+2y)=(x+y)(x-y)/2(x+y)²=(x²-y²)/2(x+y)²xy/(x+y)

∵最简公分母为（m-3）（m+3）∴m/m²-9=m/（m-3）（m+3）∴1/m-3=1(m+3)/(m-3)(m+3)=m+3/(m-3)(m+3)

m/(m-n-m²+n²)=m/[(m-n)-(m²-n²)]=m/[(m-n)-(m+n)(m-n)]=m/(m-n)(1-m-n)=m(1+m+n)/(m-

（2m-n）分之m

2x+2y=2(x+y)所以公分母2(x+y)²所以(x-y)/(2x+2y)=(x-y)(x+y)/2(x+y)²=(x²-y²)/2(x+y)²x

2mn/(4m^2-9)(2m-3)/(2m+3)分子分母同时乘(2m-3)=(2m-3)(2m-3)/(2m+3)(2m-3)=(4m^2-12m+9)/(4m^-9)

根据题意绝对值和完全平方非负所以mn-1=0m-n-2=0mn=1m-n=2（-2mn+2m+3n)-(3mn+2n-2m)-(m+4n+mn)=-2mn+2m+3n-3mn-2n+2m-m-4n-m

3/(2M-N)=3(2M-N)/(2M-N)²2MN/(4M²-4MN+N²)=2MN/(2M-N)²如果不懂,请Hi我,祝学习愉快!

2mn分之4m方—9=n分之2—9=n分之(2-9n)2m—3分之2m+3=3分之(6m-2m-3)=3分之(4m-3)再问：额不好意思啊我不小心手滑打错了应该是2mn分之4m方—9与2m—3分之2m

最简公分母是2(x+y)²x-y/2x+2y=(x+y)(x-y)/2(x+y)².xy/（x+y）^2=2xy/2(x+y)².最简公分母是(m+3)(2m-3)2mn

1/m+n=mn(m-n)/mn(m-n)(m+n)1/m^2n-mn^2=1/mn(m-n)=(m+n)/mn(m-n)(m+n)

解最简公分母为x(x-y)(x+y)∴1/(x²-y²)=x/x(x²-y²)=x/x(x-y)(x+y)1/(x²+xy)=(x-y)/x(x+y)

先通分,使分母统一为m²-n²,然后化简分子得（m+n）²,再和分母化简得m-n分之m+n.再问：上面的几分之几是个整体，后面的-号是符号，跟前面的不沾边再答：我知道就是

将分式m的2次方+2mn分之n,2n的2次方-mn分之m,m的2次方-4n的2次方分之mn通分后的结果n/(m^2+2mn)=n^2(m-2n)/[mn(m+2n)(m-2n)]m/(2n^2-mn)

n/(m²+2mn)=n/[m(m+2n)]m/(2n²-mn)=-m/[n(m+2n)]2mn/(m²-4n²)=2mn/[(m+2n)(m-2n)]所以n/