Question

CMR: \(\frac{1}{\left(x+y\right)^3}.\left(\frac{1}{x^3}+\frac{1}{y^3}\right)+\frac{3}{\left(x+y\right)^4}.\left(\frac{1}{x^2}+\frac{1}{y^2}\right)+\frac{6}{\left(x+y\right)^5}.\left(\frac{1}{x}+\frac{1}{y}\right)=\frac{1}{x^3y^3}\)

 

Answer 1

Đậu phộng rANG !

Answer 2

Ko làm đc thì đừng trl linh tinh nhé -_-

Answer 3

Xi lỗi mn bị người khác hack nick

Answer 4

Dat \(x+y=u,xy=v\left(u,v\ne0\right)\)

Ta CM:

\(\frac{1}{u^2}.\frac{\left(u^2-3v\right)}{v^3}+\frac{3}{u^4}.\frac{u^2-2v}{v^2}+\frac{6}{u^5}.\frac{u}{v}=\frac{1}{v^3}\)

\(\Leftrightarrow\frac{\left(u^2-3v\right)u^3+3uv\left(u^2-2v\right)+6uv^2}{u^5v^3}=\frac{u^5}{u^5v^3}\)

\(\Rightarrow u^5-3u^3v+3u^3v-6uv^2+6uv^2=u^5\)

\(\Leftrightarrow0=0\)(luon dung)

Answer 5

$\frac{x}{y}$