\(x^2-y^2-5x+5y=\left(x^2-y^2\right)-\left(5x-5y\right)\\ =\left(x-y\right)\left(x+y\right)-5\left(x-y\right)\\ =\left(x-y\right)\left(x+y-5\right)\)

-_-

\(x^3-3x^2-4x+12=\left(x^3-3x^2\right)-\left(4x-12\right)\\ =x^2\left(x-3\right)-4\left(x-3\right)=\left(x-3\right)\left(x^2-4\right)\\ =\left(x-3\right)\left(x-2\right)\left(x+2\right)\)

-_- lỗi bn ơi

D

nhầm tí lm j căng

\(\Leftrightarrow5x\left(x+7\right)-\left(x+7\right)=0\\ \Leftrightarrow\left(x+7\right)\left(5x-1\right)=0\\ \Leftrightarrow\left[{}\begin{matrix}x+7=0\\5x-1=0\end{matrix}\right.\Leftrightarrow}\left[{}\begin{matrix}x=-7\\x=\dfrac{1}{5}\end{matrix}\right.\)

\(\Leftrightarrow\left(2x+3\right)^3=\left(-5\right)^3\\ \Leftrightarrow2x+3=-5\\ \Leftrightarrow2x=-8\\\Leftrightarrow x=-4\)

B