①[(x+y)^2-(x+y)(x-y)]/2y
=[(x+y)(x+y-x+y)]/2y
=[(x+y)*2y]/2y
=x+y
②(-1/3a^3b^2)^2(-2ab^2)^3/(1/9a^4b^4)^2
=(1/9a^6b^4)(-8a^3b^6)/(1/81a^8b^8)
=(-8/9a^9b^10) /(1/81a^8b^8)
=-72ab^2
①[(x+y)^2-(x+y)(x-y)]/2y
=[(x+y)(x+y-x+y)]/2y
=[(x+y)*2y]/2y
=x+y
②(-1/3a^3b^2)^2(-2ab^2)^3/(1/9a^4b^4)^2
=(1/9a^6b^4)(-8a^3b^6)/(1/81a^8b^8)
=(-8/9a^9b^10) /(1/81a^8b^8)
=-72ab^2