4x2+8x+xy+2y
<-> 4x(x+2)+y(x+2)
<-> (x+2)(4x+y)
\(4x^2+8x+xy+2y\)
\(=\left(4x^2+8x\right)+\left(xy+2y\right)\)
\(=4x\left(x+2\right)+y\left(x+2\right)\)
\(=\left(4x+y\right)\left(x+2\right)\)
\(4x^2+8x+xy+2y\)
\(=\left(4x^2+8x\right)+\left(xy+2y\right)\)
\(=4x\left(x+2\right)+y\left(x+2\right)\)
\(=\left(x+2\right)\left(4x+y\right)\)