1) xy^2+x^2y^3: 2)m^2n^2+mn^3: 3)c^3d^2-c^4d^2

[tex]1)xy^{2}+x^{2}y^{3}=xy^{2}(1+xy)[/tex]
[tex]2) m^{2}n^{2}+mn^{3}=mn^{2}(m+n)[/tex]
[tex]3) c^{3}d^{2}-c^{4}d^{2}=c^{3}d^{2}(1-c)[/tex]