+ab^2)+(a^2-1)+(a^2b-ab^2)+3a^3 2)(3m^2+5mn++-3m^2)

1)(-2a^3+ab^2)+(a^2-1)+(a^2b-ab^2)+3a^3 =
-2a^3+ab^2+a^2-1+a^2b-ab^2+3a^3=
a^2+a^2b+a^3-12)(3m^2+5mn+7m^2y)-(5mn+3m^2)-(7m^3y-3m^2)= 3m^2+5mn+7m^2y-5mn-3m^2-7m^3y+3m^2=
7m^2y-7m^3y+3m^2