先化简,再求值:(x 3分之2
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原式=3x3-x3-2x3-6x2+6x2+7x+4x=15x,当x=13时,原式=15×13=-5.
=[(a²-4)/(a-2)]×1/a(a+2)=[(a+2)(a-2)/(a-2)]×1/a(a+2)=(a+2)×1/a(a+2)=1/a
m/(m-n)-n/(m+n)+2mn/(m²-n²)=[m(m+n)-n(m-n)+2mn]/(m²-n²)=(m²+n²)/(m
2x³+4x-x²/3-x-3x²+2x³=4x³-10x²/3+3x当x=-3时,上式得:4*(-3)³-10*(-3)
m²-m分之m²-2m+1=(m-1)²/m(m-1)=(m-1)/m=(92-1)/92=91/92
=(a-3)/2(a-2)÷[5/(a-2)-(a+2)(a-2)/(a-2)]=(a-3)/2(a-2)÷(5-a²+4)/(a-2)=(a-3)/2(a-2)×[-(a-2)/(a+3)
原式=-x2+x(4分),当x=-1时,原式=-2.
(1+1/(x-1))÷x/(x²-1)=x/(x-1)÷x/(x+1)(x-1)=x/(x-1)×(x+1)(x-1)/x=x+1代入可得结果等于-1
2分之3m-(2分之5m-1)+3(4-m)=2分之3m-2分之5m+1+12-3m=-4m+13=-4*3+13=1
您好:x-2>0x>22x+1<82x
原式=(x-1)(x+1)/(x+2)*(x+2)/x-1=x+1然后代入数值即可很高兴为您解答,【学习宝典】团队为您答题.请点击下面的【选为满意回答】按钮,
(a+2a+1)/(a-1)-a/(a-1)=(a+1)^2/(a+1)(a-1)-a/(a-1)=(a+1)/(a-1)-a/(a-1)=1/(a-1)由a=根号3+1,所以原式=1/(a-1)=1
再求值m平方+m-2分之1+m除于m-2+m+2分之3
原式=[2x(x+2)-x(x-2)]/(x²-4)+x/(x²-4)=(x²+7x)/(x²-4)=[x(x+7)]/[(x+2)(x-2)]代入x=5原式=
原式=2x-1-16+8x-16=10x-33将x=4/5代入上式得上式=4/5*10-33=-25
=(x+1)/((2*x+1+x^2)/x)=(x+1)/((x+1)^2/x)=(x+1)*x/(x+1)^2=x/(x+1)代入x=-3/2得到:原式=3
(a-2)分之a-(a²-2a)分之2a-a分之2=[a(a-2)]分之a²-[a(a-2)]分之(2a)-[a(a-2)]分之[2(a-2)]=[a(a-2)]分之[a²