先化简,在求值.(a 1分之2 a²-1分之a 2)-搜答案-搜狗做题网

=[(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

a是方程x^2+3x-6的根则有a^2+3a-6=0a^2+3a=6（a^2-4a+4分之a^2-4—2-a分之1）÷a^2-2a分之2=（(a+2)(a-2)/(a-2)^2+1/(a-2)）*(a

原式={[(a+2)(a-2)/(a-2)^2+[(a-2)^2/1/(a-2)]}×a(a-2)=[(a+2)/(a-2)+1/(a-2)]×a(a-2)=[(a+3)/(a-2)]×a(a-2)=

a=1/(2+√3)=2-√3原式=(a+1)(a-1)/(a-1)-√(a-1)²/[a(a-1)]=a+1+(a-1)/[a(a-1)]=a+1+1/a=2-√3+1+1/(2-√3)=

原式=(a-1)/(a+2)×(a+2)(a-2)/(a-1)²×(a+1)(a-1)=(a-2)(a+1)=a²-a-2∵a²-a=0∴原式=0-2=-2

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

[(a-2)/(a+3)]/[(a^2-4)/(2*a-6)]-[5/(a+2)]化简后等于-3/(a+2),这样就行了吧,可以带入值了

=6a平方+5a平方-10ab+5a-12a平方-10ab-3a=-a平方-20ab+2a=-2

a的平方-4分之4+2-3分之1=a的平方-4分之4+3分之5=[(2012-4)(2012+4)]分之4+3分之5=1012032分之1+3分之5=1012032分之1686721再问：真的？能分开

（a-根号3）乘（a+根号3）-a(a-6)=a^2-(√3^2)-a^2+6a=6a-3当a=√5+1/2时,原式=6*（√5+1/2）=3+6√5

问题表述不清再问：a²+2a+1a----------－------------其中a=√3+1a²-1a-1再答：3分之根号3再问：要过程再答：呵呵

,(X-2-X+2分之5)/2x+4分之x-3=[(x-2)(x+2)-5]/(x+2)×2(x+2)/(x-3)=(x²-9)/(x+2)×2(x+2)/(x-3)=(x+3)(x-3)/

（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/(a-b)-a^2/(a^2-2ab+b^2)÷[(a/a+b-a^2/(a^2-b^2)]+1=a(a-b)/(a-b)^2-a^2/(a-b)^2÷[a(a-b)/(a^2-b)-a^2/(a

原式=(a²-6a+8)-(a²-4a+3)=a²-6a+8-a²+4a-3=-2a+5=-2×(-5/2)+5=5+5=10

请放心使用有问题的话请追问再问：(2)5/3a^2nb3分之5a(a的2n次方)b再答：满意请及时采纳哦，谢谢

原式=（2aa−1-aa−1）÷a=aa−1×1a=1a−1，当a=2+1时，原式=12+1−1=12=22．

(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