solve X @ zogfly3的部落格

標題:

solve X

發問:

-4/(x+4)^2 = x+12-a/x = x-a/a 更新: 第二條問題應該係: 2-(a/x) = (x-a)/a

最佳解答:

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1._______________-4/(x+4)2=x+1_________________________-4=(x+1)(x+4)2______________(x+1)(x+4)2+4=0__________(x+1)(x2+8x+16)+4=0______x3+x2+8x2+8x+16x+16+4=0______________x3+9x2+24x+20=0_______x3+4x2+4x+5x2+20x+20=0______x(x2+4x+4)+5(x2+4x+4)=0_____________(x2+4x+4)(x+5)=0________________(x+2)2(x+5)=0________________________x+2=0 or x+5=0__________________________x= -5 or -22. _________________2–(a/x)=(x-a)/a __________________________2=(x-a)/a+a/x__________________________2=[x(x-a)+a2]/(ax)________________________2ax=x2-ax+a2________________x2-(3a)x+a2=0x2-2(x)(3a/2)+(3a/2)2-5a2/4=0_________(x-3a/2)2-(√5a/2)2=0_[x+(√5-3)a/2][x-(3=√5)a/2]=0________________x+(√5-3)a/2=0 or x-(3+√5)a/2=0__________________________x= (3-√5)a/2 or (3+√5)a/2

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