初二的几道分式通分
问题描述：
初二的几道分式通分
1.2ab分之3c,3ac^2分之b,4b^2c分之2
2.2x+2分之x+2,x^2-x-2分之x,8-4x分之3
3.5b^2c分之4a,10a^2b分之3c,-2ac^2分之5b
4.a^2+2a+1分之a-1,a^2-1分之1
答
1.2ab分之3c=3c/2ab=9bc^3/6ab^2c^2
3ac^2分之b=b/3ac^2=2b^3/6ab^2c^2
4b^2c分之2=1/2b^2c=3ac/6ab^2c^2
2.2x+2分之x+2=(x+2)/2(x+1)=2(x+2)(x-2)/4(x+1)(x-2)
x^2-x-2分之x=x/(x+1)(x-2)=4x/4(x+1)(x-2)
8-4x分之3=-3/4(x-2)=-3(x+2)/4(x+1)(x-2)
3.5b^2c分之4a,=4a/5b^2c=8a^3c/10a^2b^2c^2
10a^2b分之3c=3c/10a^2b=3bc^3/10a^2b^2c^2
,-2ac^2分之5b=-5b/2ac^2=-25ab^3/10a^2b^2c^2
4.a^2+2a+1分之a-1=(a-1)/(a+1)^2=(a-1)^2/(a-1)(a+1)^2
a^2-1分之1=1/(a-1)(a+1)=(a+1)/(a-1)(a+1)^2