Question

Cho 2 đơn thức :

\(A=\left(-2xy^3\right)^2\)

\(B=\left(3x^3y\right)^2\)

Tìm x,y biết A+B=0

Answer 1

\(A+B=0\Leftrightarrow\left(-2xy^3\right)^2+\left(3x^3y\right)^2=0\Leftrightarrow4x^2y^6+9x^6y^2=0\Leftrightarrow x^2y^2\left(4y^4+9x^4\right)=0\\ \Rightarrow\left[{}\begin{matrix}x=0\\y=0\\\left(4y^4+9x^4\right)=0\end{matrix}\right.\Rightarrow\left[{}\begin{matrix}x=0\\y=0\end{matrix}\right.\)