\(\frac{a}{b}+\frac{b}{a}=\frac{41}{20}\)

\(\Leftrightarrow\frac{b^2+a^2}{ab}-\frac{41}{20}=0\)

\(\Leftrightarrow\frac{20b^2-41ab+20a^2}{20ab}=0\)

\(\Leftrightarrow20\left(a^2-b^2\right)-41ab=0\)

\(\Leftrightarrow a^2-b^2=41ab\)

\(\Leftrightarrow\left(a+b\right)\left(a-b\right)=41ab\)

Nếu thấy đúng thì nhớ k nha