Question

tìm x; y thoả  5x⁴ + 10x² + 2y⁶ + 4y³ -6 = 0 

Answer 1

\(5x^4+10x^2+2y^6+4y^3-6=0\)

\(\Leftrightarrow5\left(x^4+2x^2+1\right)+2\left(y^6+2y^2+1\right)+7-6=0\)

\(\Leftrightarrow5\left(x^2+1\right)^2+2\left(y^3+1\right)^2+1=0\)

\(\Leftrightarrow5\left(x^2+1\right)^2+2\left(y^3+1\right)^2=-1\) ( vô lý )

Vì \(\left\{{}\begin{matrix}\left(x^2+1\right)^2\ge0\\\left(y^3+1\right)^2\ge0\end{matrix}\right.\)

Vậy pt vô nghiệm