Factorize each of the following expressions:

$2 a x+b x+2 a y+b y$

$=(2 a x+b x)+(2 a y+b y)$     [Grouping the expressions]

$=x(2 a+b)+y(2 a+b)$

$=(x+y)(2 a+b)$        [Taking $(2 a+b)$ as the common factor]