(x÷3+1)x2+3=(x÷2.5+1)x2一77

(x÷3+1)x2+3=(x÷2.5+1)x2一77 ①x/(x2-1) ·(x2+x)/x2其中x=2 ②(x2-1)/(x2+4x+4)÷(x+1).(x+2﹚/﹙1-x﹚其中x=-3 先化简,再求值 x+3/x2-1 ÷(x+3)(x-1)/x2-2x+1,其中x=2007, 已知：√x=√a+1/√a求（x2+x-6）/x÷(x+3)/(x2-2x)-[(x-2)+√(x2-4x)]/[(x-2)-√(x2-4x)]的值 3/x2 -3x+2-1/x-2=1/x2 -x+4/x2 -2x x+2÷x2-2x-1÷x2-4x+4x=1-√3 x2-3x+1=0 x2/(x4-x2+1) (x2-2)÷(x2-2)=1,所以3x=3,x=1 已知 x÷(x2-x+1)=1/3,求x2÷(x4+x2+1)的值 若 x2-3x+1=0,求（2x2×x3-5x2×x2+2 x3-8x2 ）÷（x2+1 ）的值 x+1/x=3,求x2/x4+x2+1 解方程：X2--1/8(X2+2X)+X2+2X/3(X2--1)=11 化简 (x2-2x+1／x2-1)÷﹙1+(x-3／x+1) x2-3x-1=0,求①x2 1/x2;②x2-1/x2 函数f(x)=3x/x2+x+1 (x 函数f(x)=3x/x2+x+1 (x (x+1)(x2-x+1)+(x-2)(x2+2x+4),其中x=-3/2 解方程：1/x2+x +1/x2+3x+2 +1/x2+5x+6 +1/x2+7x+12 +1/x2+9x+20=5/x2+11x-708解方程：1/x2+x +1/x2+3x+2 +1/x2+5x+6 +1/x2+7x+12 +1/x2+9x+20=5/x2+11x-708