已知x x x 1=1 3,求分式的值．-搜答案-大师作文网

1）由1/x-1/y=5,得(y-x)/xy=5,所以y-x=5xy,即x-y=-5xy(3x+5xy-3y)/(x-3xy-y)=[3(x-y)+5xy]/[(x-y)-3xy]=(-15xy+5x

∵a－1/a＝6∴﹙a－1/a﹚²＝6²a²＋1/a²＝38a²＋1/a²＋1＝38＋1＝39.

x=0:10;a=[2,1,1];b=[1,0,1,1,9];y=polyval(a,x)./polyval(b,x)

x+1/x=3(x+1/x)^2=3^2=9x^2+1/x^2+2=9x^2+1/x^2=7

由已知1,分母为0,b=6,由已知2,a=-5.则6a+9b=6*6+9*（-5）=-9

y²-3y+1=0两边除以y得y-3+1/y=0y+1/y=3两边平方得y²+2+1/y²=9∴y²+1/y²=7y²+1+1/y²

2x=-yy=-2xxy/(x^2-y^2)=x*(-2x)/[x^2-(-2x)^2]=-2x^2/[x^2+4x^2]=-2x^2/5x^2=-2/5

x+x分之一=3两边平方：x²+1/x²+2=9x²+1/x²=9-2=7

两边乘x(x+1)3(x+1)+x(kx+3)=2x(x+1)有增根则分母等于0x(x+1)=0x=0,x=-1x=0代入3(x+1)+x(kx+3)=2x(x+1)3=0,不成立x=-1代入3(x+

由1/x-1/y=2001得：y-x/xy=2001所以：xy/y-x=1/2001xy/x-y=-1/2001x-xy-y/(x-y)=x-y-xy/(x-y)=1-xy/(x-y)原式=1+1/2

1/a＋1/b＝5/（a＋b）（a＋b）²＝5aba²＋b²＝3ab（a²＋b²）/ab＝3a/b＋b/a＝3.

依据题意：当x=4时,分母2x+b=0∴8+b=0b=-8当x=-3时,分子x-a=0∴-3-a=0a=-3∴（a+b）/（a-2b）=（-3-8）/（-3+16）=-11/13【很高兴为你解决以上问

1/(a+1)-(a+3)/(a^2-1)*(a^2-2a+1)/(a^2+4a+3)=1/(a+1)-(a+3)/(a+1)(a-1)*(a-1)^2/(a+3)(a+1)=1/(a+1)-(a-1

X=-2时,分式无意义,所以a-2b+3×(-2)=0,即a-2b=6x=1时,分式的值为0,所以1+a+b=0,即a+b=-1a、b的两个方程联立解得：a=4/3,b=-7/3

2的m次方=2的(-4)次方∴m=-4(1/3)的n次方=273的(-n)次方=3³-n=3∴n=-3∴n^m=(-3)^(-4)=1/81

1.最简单的方法是用数代（填空题的话）ab互为倒数设a=2则b=1/22/3+1/3=12.移项x+7/x+6-x+6/x+5=x+10/x+9-x+9/x+8-1/X^2+11x+30=-1/X^2

y=4x带入3x-y=3x-4x=-xx+y=x+4x=5x(x+y)/(3x-y)=5x/(-x)=-5

原式=[(x-y)/x]/[(x²-2xy+y²)/x]=(x-y)/(x-y)²因为x-y=2011-2012=-1所以原式=-1/（-1）²=-1

x+1/x=3(x+1/x)^2=3^2=9x^2+1/x^2+2=9x^2+1/x^2=7

同学,你这道题是不是题干有问题啊?分子上这一项你确定是ab²?这样的话就会出现b的3次方,那就求不出分式的值了,所以下面把ab²改为ab了.2a=3b,得a=3b/2分子：9b&#