Factorize the following :
(1)`9x^2y+3a x y`
(2) `16 m-4m^2`
(3)`-4a^2+4a b-4c a`
(4) `x^2y z+x y^2z+x y z^2`
(5) `a x^2y+b x y^2+c x y z`

Explanation

Given:

(1)`9x^2y+3a x y`

`=> 3xy(3x+a)`

(2) `16 m-4m^2`

`=> 4m(4-m)`

(3)`-4a^2+4a b-4c a`

`=> 4a(-a+b-c)`

(4) `x^2y z+x y^2z+x y z^2`

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