Question

Answer 1

Bài 1: 

A=(3-x)(3+x)

B=(x-y-4)(x-y+4)

Answer 2

\(1,\\ A=\left(3-x\right)\left(3+x\right)\\ B=\left(x-y\right)^2-16=\left(x-y-4\right)\left(x-4+y\right)\\ 2,\\ a,\Leftrightarrow x\left(x^2-3\right)=0\Leftrightarrow\left[{}\begin{matrix}x=0\\x^2=3\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x=0\\x=\sqrt{3}\\x=-\sqrt{3}\end{matrix}\right.\\ b,\Leftrightarrow x^2+3x+x+3=0\\ \Leftrightarrow\left(x+3\right)\left(x+1\right)=0\Leftrightarrow\left[{}\begin{matrix}x=-3\\x=-1\end{matrix}\right.\)