写清楚一些好吗
...a-2\/a+2a - a-1\/a+4a+4)除于a-4\/a+2,其中a满足:a2+2a-1=0_百度...
先把总式化之最简,为（6a2+4a-3）（a+2）\/(a2-4a),将条件中a2+2a=1代入,可将化简式中平方消去,从而再将a2+2a-1=0解得的根代入,即得最终值
先化简.再求值 (a-2\/a^2+2a - a-1\/a^2+4a+4)÷a-4\/a+2 其中a满足 a^2...
[(a-2)\/(a^2+2a)-(a-1)\/(a^2+4a+4)]\/a-4\/a+2,其中a满足a^2+2a-1=0 因为a^2+2a-1=0, 所以a^2+2a=1, 所以[(a-2)\/(a^2+2a)-(a-1)\/(a^2+4a+4)]\/[(a-4)\/(a+2) =[(a-2)\/a(a+2)-(a-1)\/(a+2)^2]*[(a+2)\/(a-4)] =[(a-2)(a+2)\/....
...a-2\\a2+2a-a-1\\a2+4a+4)\\a-4\\a+2,其中a2+2a-1=0
因为a^2+2a-1=0,所以a^2+2a=1,所以[(a-2)\/(a^2+2a)-(a-1)\/(a^2+4a+4)]\/[(a-4)\/(a+2)=[(a-2)\/a(a+2)-(a-1)\/(a+2)^2]*[(a+2)\/(a-4)]=[(a-2)(a+2)\/a(a+2)^2-a(a-1)\/a(a+2)^2]*[(a+2)\/(a-4)]=[(a^2-4-a^2+a)\/a(a+2)^2...
...a-1\/a²+4a+4)】÷(a-4\/a+2),其中a=根号2-1
：【（a-2\/a²+2a）-（a-1\/a²+4a+4）】÷（a-4\/a+2）=[(a-2)\/a(a+2)-(a-1)\/(a+2)²]×(a+2)\/(a-4)=[(a-2)(a+2)-a(a-1)]\/a(a+2)² ×(a+2)\/(a-4)=(a²-4-a²+a)\/a(a+2)(a-4)=1\/a(a+2)当a=√2-1时...
先化解在求值(a-2\/a的 2次方+2a)-a-1\/a的2次方+4a+4)\/a-4\/a+2,其中a
a²+2a-1=0a²+2a=1(a-2\/a的二次方+2a-a-1\/a的二次方+4a+4)x(a+2\/a-4)=[(a-2)\/a(a+2)-(a-1)\/(a+2)²]×(a+2)\/(a-4)=[(a²-4-a²+a)\/a(a+2)²]×(a+2)\/(a-4)=(a-4)\/a(a+2)²×(a+2)\/(a-4)=1\/a...
...再求值:(a?2a2+2a?a?1a2+4a+4)÷a?4a+2,其中a=-1.(2)化简:(x-y...
（1）原式=[a?2a(a+2)-a?1(a+2)2]?a+2a?4=(a+2)(a?2)?a(a?1)a(a+2)2?a+2a?4=a?4a(a+2)2?a+2a?4=1a(a+2)，当a=-1时，原式=-1；（2）原式=x2-y2+x-y+x+y=x2-y2+2x．
先化简,再求值 a-1\/a+2×a^2-4\/a^2-2a+1÷1\/a^2-1,其中a满足a^2-a=0
因为a^2-a=0，所以a^2=a,代入下式:原式=a-1\/a+2×a^2-4\/a^2-2a+1÷1\/a^2-1 =a-1\/a+2*a-4\/a-2a+1÷1\/a-1 =a-1\/a+2a-4\/a-2a+a-1 =2a-5\/a-1 因为a^2-a=0，所以 a=0或者a=1 (1)当a=0 时，1\/a无意义，所以a不能等于0 (2)当a=1 时，原式=2*...
...2a分之a+2-a²-4a+4分之a-1)÷a分之4-a,其中a=2分之1
a+2)\/(a²-2a)-(a-1)\/(a²-4a+4)]÷(4-a)\/a ={(a+2)\/[a(a-2)]-(a-1)\/(a-2)²}÷(4-a)\/a =[(a²-4)-a(a-1)]\/[a(a-2)²]*a\/(4-a)= -3\/[(a-2)²(4-a)]当 a=1\/2 时 原式= -3\/(9\/4*7\/2)=- 8\/21 ...
先化简,再求值:(a2?4a2?4a+4-12?a)÷2a2?2a,其中a是方程x2+3x-10=0...
原式=[(a+2)(a?2)(a?2)2+1a?2]?a(a?2)2=a+2+1a?2?a(a?2)2=a+3a?2?a(a?2)2=a2+3a2，∵a是方程x2+3x-10=0的根，∴a2+3a-10=0，即a2+3a=10，∴原式=102=5．
先化简再求值:(a-1)\/(a^2-4a+4)×(a^2 - 4)\/(2a-2),其中a=-1
=a-1\/a^2-4a+4(a+1)(a-1)\/2(a-1)=a-1\/a^2-4a+2(a+1)=a-1\/a^2-4a+2a+2 =a-1\/a^2-2a+2 =a-1\/a^2-2(a-1)=a-1\/a^2-2(a-1)a^2\/a^2 =((a-1)-2(a-1)a^2)\/a^2 =(a-1-2a^3+a^2)\/a^2 a=-1时，原式=1 【【如果回答让你满意， 请采纳...
