\(=x\left(a-b\right)-\left(a^2-2ab+b^2\right)=\)

\(=\left(a-b\right)x-\left(a-b\right)^2=\)

\(=\left(a-b\right)\left[x-\left(a-b\right)\right]=\left(a-b\right)\left(x-a+b\right)\)

\(x^2-xy+x-y\)

\(=x\left(x-y\right)+\left(x-y\right)\)

\(=\left(x+1\right)\left(x-y\right)\)

\(x^2-xy+x-y\)

\(=x\left(x-y\right)+\left(x-y\right)\)

\(=\left(x+1\right)\left(x-y\right)\)

Bạn xem lại đề

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

\(\Leftrightarrow3\left(x+4\right)-x\left(x+4\right)\)

\(\Leftrightarrow\left(3-x\right)\left(x+4\right)\)

\(=\left(x-y\right)\left(x+y\right)-10\left(x+y\right)=\)

\(=\left(x+y\right)\left(x-y-10\right)\)

= (x - y). (x + y) - 10 ( x - y)

= [( x + y) - 10)] . ( x - y)

  \(x^2\).(\(x\) - 1) + 16.( 1 - \(x\))

= \(x^2\).(\(x-1\)) - 16.( \(x-1\))

= (\(x\) - 1).(\(x^2\) - 16)

= (\(x\) - 1).(\(x\)² - 4²)

= (\(x\) - 1).(\(x\) - 4)(\(x\) + 4)

= ( x - 2y ) ( x + 2y ) - 2 ( x + 2y )

= ( x + 2y ) ( x - 2y - 2 )

\(x^2-2x-4y^2-4y\)

\(=x^2-4y^2-2x-4y\)

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

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

= ( a + b ) mũ 2 - c ( a + b )

= ( a + b ) ( a + b - c )