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先化简,再求值:(x+1)(2x%1)%(x%3)²,...

原式=2x2-x+2x-1-x2+6x-9=x2+7x+10,当x=-2时,原式=4-14+10=0.

(2x-1)²+(x+2)(x-2)-4x(x-1) =4x²+1-4x+x²-4-4x²+4x =x²-3 =3²-3 =6

(2x-1)2+(x+3)(x-3)-4x(x-1),=4x2-4x+1+x2-9-4x2+4x,=x2-8,当x=-2时,原式=x2-8=(-2)2-8=4-8=-4.

最后一项是分子是x+1 还是1?

x²-x-1=0 x²-x=1 x²-x+1/4=1+1/4 (x-1/2)²=5/4 x-1/2=±√5/2 x=1/2±√5/2=(1±√5)/2 x²=(1±2√5+5)/2=(6±2√5)/2=3±√5 x³=(1±3√5+15±5√5)/8=(16±8√5)/8=2±√5 (1-3/x+2)÷x-1/x²+2x-x/x+1 =(3-3/x)÷x-1/x²+2...

原式=(x-1)/(x-x²)-1/(x+3)×(x+3)/(x²+2x+1) =-x-1/(x+1)² 代入x=√2-1,得 原式=1-√2-1/(√2-1+1)²=1-√2-1/2=1/2-√2 题目不知道是不是这样,如果不是可以追问我

(1)3(2x+1)+2(3-x)=6x+3+6-2x=4x+9,当x=-1时,原式=4×(-1)+9=-4+9=5;(2)3(a+b)2-7(a-b)-2(a+b)2+5(a-b)+2=(a+b)2-2(a-b)+2,当a=-2,b=-3时,原式=[(-2)+(-3)]2-2×[-2-(-3)]+2=(-5)2-2×(-2+3)+2=25-2×1+2=25-...

[1/(x+1)+(x^2-2x+1)(x^2-1)]/[(x-1)/(x+1)] =[1/(x+1)+(x-1)^2/(x-1)(x+1)]/[(x-1)/(x+1)] =[1/(x+1)+(x-1)/(x+1)]*(x+1)/(x-1) =1/(x+1)*(x+1)/(x-1)+(x-1)/(x+1)*(x+1)/(x-1) =1/(x-1)+1 =(1+x-1)/(x-1) =x/(x-1) =3/(3-1) =3/2

原式=-x?2x?1?(x?1)2x?2=-x+1,解不等式组得-1<x≤2,符合不等式解集的整数是0,1,2,当x=0时,原式=2.

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