先化简 再求值:(a-1分之2-a分之1)÷a²-2a 1分之a² a
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原式=(a-2)/a(a+2)-(a-1)/(a+2)平方=(a平方-2a-a平方+a)/a(a+2)平方=-1/(a+2)平方=-1/5
题目有误吧(x-x)x-1分之4(x-x)+(x-2)再问:(x方-x)(x-2)方再答:
答:题目最后是tan6?没写全吧?是不是tan60°?[2/(a+1)+(a+2)/(a²-1)]÷[a/(a+1)]=[2(a-1)+(a+2)]/[(a+1)(a-1)]×(a+1)/a
∵a=2-√3,∴1-a=√3-1>0a-1分之1-2a+a2-a分之根号a2-2a+1-a分之1=(a-1)^2/(a-1)-(1-a)/a-1/a=a-1-1/a+1-1/a=a-2/a=2-√3
=[(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
(a²-4a+3)分之(a²-4)×(a²+3a+2)分之(a-3)-(a²-1)分之(a+3)=(a+2)(a-2)/(a-3)(a-1)x(a-3)/(a+
原式=ab(a-2b)分之3a²(a-2b)=b分之3a
先化简再求值(1/2a+1/3b)(1/3b-1/2b)-(1/3b-1/2a)^2+(-1/3b-1/2a)^2,其中a=1/2,b=-1/3(1/2a+1/3b)(1/3b-1/2a)-(1/3b
(a-5)(a+1)/(a²-5a)=(a-5)(a+1)/a(a-5)=(a+1)/a=1+1/a=1+1/(-1/3)=1-3=-2如果不懂,祝学习愉快!再问:题目错了,是这样的;先化简
a=2/﹙1-√3﹚=﹣﹙√3+1﹚﹙a²-1﹚/﹙a-1﹚+√﹙a²+2a+1﹚/﹙a²+a﹚-1/a=a+1-1/a-1/a=a+1-2/a=﹣√3-1+1+2/﹙√
1、原式=2a/(a+2)(a-2)-1/(a-2)=(2a-a-2)/(a+2)(a-2)=1/(a+2)当a=√3-2时,原式=1/√3=√3/3.2、原式=43-12√35.3、原式=15/2√
解-a²+(-4a+3a²)-(5a²+2a-1)=-a²-4a+3a²-5a²-2a+1=(-a²+3a²-5a
a=根号2-1∴a-1
解(a²+2a+1)/(a²-1)-a/(a-1)=(a+1)²/(a-1)(a+1)-a/(a-1)=(a+1)/(a-1)-a/(a-1)=(a+1-a)/(a-1)
(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
a^2-1+2-1/a=a^2-1/a+1,a=-3代入,得原式=31/3
解原式=[(a+2)/a²]÷[(a²-4)/a]=(a+2)/a²×a/(a-2)(a+2)=1/a(a-2)=1/(√3)(√3-2)=1/(3-2√3)=(3+2√
原式=(a+b)(a-b)/ab(a+b)÷(a²+b²-2ab)/2ab=(a-b)/ab×2ab/(a-b)²=2/(a-b)=2/(3+√5-3+√5)=√5/5