a)
(1+\sqrt2)^2=1+2\sqrt2+2=3+2\sqrt2
b)
(\sqrt3-1)^2=(\sqrt3)^2-2\sqrt3+1=3-2\sqrt3+1=4-2\sqrt3
c)
(4-\sqrt5)(4+\sqrt5)=4^2-(\sqrt5)^2=16-5=11
d)
(\sqrt6+\sqrt5)(\sqrt6-\sqrt5)=6-5=1
e)
(2\sqrt5-\sqrt{10})^2=4*5-4\sqrt{50}+10=20-4\sqrt{25*2}+10=30-4*5\sqrt2=30-20\sqrt2