giải
(47.53)=(47+3)(53-3)
=50.50=2500
e/(x-y^2)^3=x^3-3.x^2.y+3.x.y^2-y^3
d/(x-2)^3=x^3-3.x^2.2+3.x.2^2-2^3
c/(2x-1)^3=2x^3-3.2x^2.1+3.2x.1^2-1^3
(2x+1)^3=2x^3+3.2x^2.1+3.2x.1^2+1^3