3 2-1 4(X 2-(X-2) 4)=1 10(5X-5(X 3) 4)
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要使根号(x2+2x+4)-根号(x2-x+1)
(x²+1)²-4x(x²-1)=(x²-1)²-4x(x²-1)+4x²=(x²-1-2x)²(x^4-2x
等式两边同时乘以(x+3)(x-2)(x+2)就可以去分母了
(x^2+2x+4)(x^2+2x-3)-8设m=x^2+2x+4原式=m(m-7)-8=m^2-7m-8=(m+1)(m-8)=(x^2+2x+4+1)(x^2+2x+4-8)=(x^2+2x+5)
x2-3x+2=(x-1)(x-2),x2-18x+32=(x-16)(x-2),x2+x-6=(x+3)(x-2),公因式为x-2.故选:D.
X^2-5x=14->x=-2或x=72x^2-x-2x+1-[x^2+2x+1]+1=x^2-5x+1=15
(x^2+1)^2-4x(x^2-1)=(x^2-1)^2-4x(x^2-1)+4x^2=[x^2-1-2x]^2
因式分解(x2-2x-2)(x2-2x+4)+9设x^2-2x=y原式=(y-2)(y+4)+9=y^2+2y-8+9=y^2+2y+1=(y+1)^2=(x^2-2x+1)^2=(x-1)^4
原式=x3+8+x3-1=2x3+7=-16/27+7=173/7
两边乘x(x+1)(x-1)2(x-1)+3(x+1)=4x2x-2+3x+3=4x5x+1=4xx=-1经检验,x=-1时分母x+1=0增根,舍去方程无解
原式=(5-3-2)x2+(-5+6)x+(4-5)=x-1
原式=3x2-[7x-4x+3-2x2]=3x2-7x+4x-3+2x2=5x2-3x-3
原式=[x+2x(x-2)-x-1(x-2)2]÷x2-16x2+4x=[x2-4x(x-2)2-x2-xx(x-2)2]÷x2-16x2+4x=x-4x(x-2)2•x(x+4)(x+4)(x-4)
(X2-5x+4)(x2-X-2)-72=(x-1)(x-4)(x-2)(x+1)-72=(x-1)(x-2)(x-4)(x+1)-72=(x2-3x+2)(x2-3x-4)-72=(x2-3x)2-
原式=5x²-x²-(4x-x²)+2(x²-3x)=4x²-4x+x²+2x²-6x=7x²-10x
令a=x+1/xa²=x²+2+1/x²2(a²-2)-9a+14=0(2a-5)(a-2)=0x+1/x=5/22x²-5x+2=0(2x-1)(x
(5x+2-x+2)÷x-32x2+4x=(5x+2-x-21)•2x(x+2)x-3=5-(x+2)(x-2)x+2•2x(x+2)x-3=-(x+3)(x-3)x+2•2x(x+2)x-3=-2x
解题思路:这个是因式分解问题。由完全平方公式,再应用换元法可以得到结果.解题过程:
原式=2x/[(x-2)(x+1)]*(x+1)/(x-1)-x(x+2)/[(x+2)(x-2)]=2x/[(x-2)(x-1)]-x/(x-2)=[2x-x(x-1)]/[(x-2)(x-1)]=
解题思路:利用一元二次方程计算解题过程:最终答案:略