计算①x-3分之2-x²-9分之6:②1 x-3分之1 3-x分之1-x

=3/3x-2/3x+x/(3x-2)=1/3x+x/(3x-2)=(3x-2+3x²)/3x(3x-2)=(3x²+3x-2)/(9x²-6x)

x^2/(x-3)-(2x-3)/(3-x)+(2x+6)/(3-x)=x^2/(x-3)+(2x-3)/(x-3)-(2x+6)/(x-3)=[x^2+(2x-3)-(2x+6)]/(x-3)=(x

(x^2-1/9)÷(3x+1)=(x-1/3)(x+1/3)÷(3x+1)=(x-1/3)÷3=x/3-1/9

（9-x²）分之2x+x-3分之一-x²+6x+9分之-2=2x/(3+x)(3-x)-1/(3-x)+2/(x+3)²=[2x(x+3)-(x+3)²+2(3

原式=(x^2+3x)/(x^2+x-6)-(x+2)/(x^2-4)=x(x+3)/(x+3)*(x-2)-(x+2)/(x+2)*(x-2)=x/(x-2)-1/(x-2)=(x-1)/(x-2)

x的平方-9分之1-x-3分之1除以x-1分之6+2x=1/(x^2-9)-1/(x-3)*(x-1)/2(3+x)=(2-(x-1))/2(x^2-9)=(3-x)/2(x^2-9)=-(x-3)/

原式=[(1-1分之x+5)-(1-1分之x+4))+(1-1分之x+3)-(1-1分之x+2)]*[(x+3)(x+5)]\(x^2+7x+13)=[(1分之x+2)-(1分之x+3)+(1分之x+

[(x+2)+1]/(x+2)-[(x+1)+1]/(x+1)=[(x+4)+1]/(x+4)-[(x+3)+1]/(x+3)1+1/(x+2)-1-1/(x+1)=1+1/(x+4)-1-1/(x+

)【(x²-2x+1)/(x²-1)】÷【(x-1)/(x²+x)】=【(x-1）²/(x+1)（x-1)】÷【(x-1)/x(x+1)】=【(x-1）/(x+

思路：我们知道：1/3*2=(3-2)/3*2=3/3*2-2/3*2=1/2-1/3类比得：1/n*(n-1)=[n-(n-1)]/n*(n-1)=n/n*(n-1)-(n-1)/n*(n-1)=1

1.计算：x-y分之x+y+y-3分之2x=(x+y)/(x-y)+2x/(y-3)=((x+y)(y-3)+2x(x-y))/(x-y)(y-3)=(xy-3x+y^2-3y+2x^2-2xy)/(

x的平方-2x+1分之x-3÷x-1分之x的平方-9=[(x-3)/(x-1)²]*[(x-1)/(x+3)*(x-3)]=1/(x-1)(x+3)

⑴(x+2/x-1)*(x^2-1/x^2-4)=（（x+2)*(x+1)*(x-1)）/（（x-1）*（x-2)*x+2)=（x+1)/(x-2)⑵(x^2+3x+2/x^2-3x+2)*(2x-x

化简：原式=x^2/2-2x+2=1/2(x^2-4x+4)=1/2(x-2)^2

原式=2x/(x^2-4)-1/(2-x)+3/(x+2)=2x/(x-2)(x+2)+1/(x-2)+3/(x+2)=[2x+(x+2)+3(x-2)]/(x-2)(x+2)=(6x-4)/(x-2

解原式=3(2-x)/3(x-4)(x+2)+(x+4)(x-4)/3(x+2)(x-4)=(6-3x)/3(x-4)(x+2)+(x²-16)/3(x+2)(x-4)=(6-3x+x

原式=1/(x-3)-1/2(x+3)-x/(x-3)²=[2(x+3)(x-3)-(x-3)²-2x(x+3)]/[2(x+3)(x-3)²]=(2x²-18

裂项相消：1/[x(x+1)]+1/[(x+1)(x+2)]+1/[(x+2)(x+3)]+...+1/[(x+2011)(x+2012)]=1/x-1/(x+1)+1/(x+1)-1/(x+2)+1

注:分子/分母(1/x-3)+(1/9-x^2)-(x-1/6-2x)通分:=2(x+3)/2(x+3)(x-3)+12/2(9-x^2)-(x-1)(3+x)/2(3-x)(3+x)=2x+6/2(