Question

\(\left(x+\sqrt{x^2+9}\right)\left(y+\sqrt{y^2+9}\right)=9\)

\(P=2x^4-y^2+6xy+8y^2-10x-2y+2024\)

GTNN

Answer 1

Ta có:

\(\left(x+\sqrt{x^2+9}\right)\left(\sqrt{x^2+9}-x\right)=9\)

\(\Rightarrow\sqrt{x^2+9}-x=y+\sqrt{y^2+9}\)

\(\Leftrightarrow\left(x+y\right)\left(1+\frac{y-x}{\sqrt{x^2+9}+\sqrt{y^2+9}}\right)=0\)

\(\Rightarrow x+y=0\)

\(P=2x^3\left(x+y\right)-......\)(xem lại đề)

Answer 2

nhỡ vế \(1+\frac{y-x}{\sqrt{x^2+9}+\sqrt{y^2+9}}=0\) thì sao