(1)-20a-15ax
=-5a(4+3x)
(2)-8a^2+12a^2y^2-16ay^2
=-4a(2a-3ay^2+4y^2)
(3)9m^2+6mn+n^2;
=(3m+n)^2
(4)2x^2+4x+2
=2(x^2+2x+1)
=2(x+1)^2
(1)-20a-15ax
=-5a(4+3x)
(2)-8a^2+12a^2y^2-16ay^2
=-4a(2a-3ay^2+4y^2)
(3)9m^2+6mn+n^2;
=(3m+n)^2
(4)2x^2+4x+2
=2(x^2+2x+1)
=2(x+1)^2