x^2+(81x^2)/((9+x)^2)=40
1个回答
关注
展开全部
亲,您好,很高兴为您解答呢!x^2+(81x^2)/((9+x)^2)=40,解法如下:
咨询记录 · 回答于2023-06-26
x^2+(81x^2)/((9+x)^2)=40
亲,您好,很高兴为您解答呢!x^2+(81x^2)/((9+x)^2)=40,解法如下:
解法 x≠-9原方凯升程可变为[x^2-18x^2/(x+9)+81x^2/(x+9)^2]+18x^2/(x+9)-40=0[x-9x/(x+9)]^2+18x^2/(x+9)-40=0[x^2/(x+9)]^2+18x^2/(x+9)-40=0令x^2/(x+9)=a∴a^2+18a-40=0∴(a+20)(a-2)=0∴a=-20或a=2当a=-20时,x^2/(x+9)=-20,即x^2+20x+180=0,△<0,无姿孙搜迹历实根当a=2时,x^2/(x+9)=2,即x^2-2x-18=0∴x1=1+√19,x2=1-√19