若分式4x-9 3x²-x-2
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=x\(2-x)-(2+x)(2-x)\(2-x)^2=x\(2-x)-(2+x)\(2-x)=(x-2-x)\(2-x)=-2\(2-x)=2\(x-2)
(x-4)(x-2)/(x^2+4x+4)=0即(x-4)(x-2)/(x+2)²=0分母不能为零所以X≠-2,分子为零,X=4或2
由x2-x-2=0⇒x=2或x=-1.当x=2时,分母x2+2x+1=9≠0,分式的值为0;当x=-1时,分母x2+2x+1=0,分式没有意义.所以x=2.
X=-6x=-6(X/(X-2))*((X-6)/(X-3))=1-
1,x-5/x-4=4-2x/4-xx-5=2x-4x=4-5x=-12,6x-1/3x+2=4x-7/2x-512x^2-13x-14=12x^2-32x+519x=19x=13,(x/x-1)-(
算得比较急,很可能算错.不过方法应该没大问题1.分子=2x^5-5x^4-x^3+x^2-6x=(x^2-3x+1)*(2x^3+x^2)-6x=-6x分子是用短除法算的分母=3x所以原式=-22.a
4/5x+x/(5x-25)=5/(x^2-5x)(4x-20)/5x(x-5)+x^2/5x(x-5)=25/5x(x-5)4x-20+x^2=254x+x^2=45x^2+4x+2^2=45(x+
2x+1=02(2x+1)/(X-2)(2X+1)无意义
(x²-4)/(x+1)(x-2)]=0[(x+2)(x-2)]/[(x+1)(x-2)]=0(x+2)/(x+1)=0∴x+2=0x=-2再问:这是初二数学。第一课分式。。请您在清楚点。。
∵当△=b2-4ac<0时,x2+4x+m=0无解,即42-4m<0,解得m>4,∴当m>4时,不论x取何实数,分式总有意义.故答案为m>4.
x/x^2-3x+1=2则(x^2-3x+1)/x=1/2所以x-3+1/x=1/2所以x+1/x=7/2两边平方,得x²+1/x²+2=49/4所以x²+1/x&sup
(X/(X-2))*((X-6)/(X-3))=1->X(X-6)=(X-2)(X-3)->X^2-6X=X^2-5X+6->X=-6
A/x-2+B/x-5=(AX-5A+BX-2B)/(X-2)(X-5)=[(A+B)X-(5A+2B)]/(X-2)(X-5)而它又等于4X+1/(x-2)(x-5)即4=A+B1=-(5A+2B)
4x/2x-1=2x+1/x-2方程两边都乘以(2x-1)(x-2)4x(x-2)=(2x+1)(2x-1)4x^2-8x=4x^2-1-8x=-1x=1/8经检验:x=1/8是方程的解.
=(x+2)/x(x-2)-(x-1)/(x-2)²=(x+2)(x-2)/x(x-2)²-x(x-1)/x(x-2)²=(x²-4-x²+x)/x(
(x-2)/(x+2)=(x+2)/(x-2)+16/(x²-4)方程两边同时乘(x²-4)(x-2)²=(x+2)²+16x²-4x+4=x
由题意可得x2-9=0,解得x=±3,又∵x2+3x≠0,解得x=3.
两边同乘x²-4(x-2)²=(x+2)²+16x²-4x+4=x²+4x+4+16-8x=16x=-2
因为:x^2-3x+1=0,所以:x+1/x=3所以:(x^4+x^2+1)/x^2=x^2+1+1/x^2=(x+1/x)^2-2+1=9-1=8所以:x^2/(x^4+x^2+1)=1/8
4x/2x-1=2x-1/x-2(2x-1)*(2x-1)=4x*(x-2)x=-1/4