А)(а+7-4)((a+7)^2+(a+7)4+16)=(a+3)(a^2+14a+49+4a+28+16)=
=(a+3)(a^2+18a+93)
б)(9b+5-3)((9b+5)^2+(9b+5)3+9)=(9b+2)(81b^2+90b+25+27b+15+9)=
=(9b+2)(81b^2+117b+49)
г) (2x+y-2x+y)((2x+y)^2+(2x+y)(2x-y)+(2x-y)^2)=
=2y(4x^2+4xy+y^2+4x^2-y^2+4x^2-4xy+y^2)=2y(12x^2+y^2)
д)(4x+5y-4x+5y)((4x+5y)^2+(4x+5y)(4x-5y)+(4x-5y)^2)=
=10y(16x^2+40xy+25y^2+16x^2-25y^2+16x^2-40xy+25y^2)=
=10y(48x^2+25y^2 )