\(1,ax+ay+bx+by\)
\(=\left(ax+ay\right)+\left(bx+by\right)\)
\(=a\left(x+y\right)+b\left(x+y\right)\)
\(=\left(x+y\right)\left(a+b\right)\)
\(2,ax+ay+2x+2y\)
\(=\left(ax+ay\right)+\left(2x+2y\right)\)
\(=a\left(x+y\right)+2\left(x+y\right)\)
\(=\left(x+y\right)\left(a+2\right)\)
\(3,ax+ay-bx-by\)
\(=\left(ax+ay\right)-\left(bx+by\right)\)
\(=a\left(x+y\right)-b\left(x+y\right)\)
\(=\left(x+y\right)\left(a-b\right)\)
\(4,ax+ay-2x-2y\)
\(=\left(ax+ay\right)-\left(2x+2y\right)\)
\(=a\left(x+y\right)-2\left(x+y\right)\)
\(=\left(x+y\right)\left(a-2\right)\)