\(x\left(x-y\right)+\left(x-y\right)=\left(x+1\right)\left(x-y\right)\)
\(\left(z-5\right)\left(x+y\right)\)
\(\left(3x-5\right)\left(x-y\right)\)
\(\left(x^2-4\right)\left(x-3\right)=\left(x-2\right)\left(x+2\right)\left(x-3\right)\)
Bài 4:
a: Ta có: \(2\left(x+3\right)-x^2-3x=0\)
\(\Leftrightarrow\left(x+3\right)\left(2-x\right)=0\)
\(\Leftrightarrow\left[{}\begin{matrix}x=-3\\x=2\end{matrix}\right.\)
b: Ta có: \(4x^2-25-\left(2x-5\right)\left(2x+7\right)=0\)
\(\Leftrightarrow\left(2x-5\right)\left(2x+5-2x-7\right)=0\)
\(\Leftrightarrow2x-5=0\)
hay \(x=\dfrac{5}{2}\)
