a)
(3-\sqrt5)^3=3^3-3*3^2*\sqrt5+3*3*(\sqrt5)^2-(\sqrt5)^3=27-27\sqrt5+9*5-5\sqrt5=
27+45-32\sqrt5=72-32\sqrt5
b)
(3\sqrt5 -2\sqrt3)^2 + (2\sqrt5 +3\sqrt3)^2=
9*5-2*3\sqrt5*2\sqrt3+4*3+4*5+2*2\sqrt5*3\sqrt3+9*3=
45-12\sqrt{15}+12+20+12\sqrt{15}+27=104
zastosowane wzory skróconego mnożenia:
(a-b)^3=a^3-3a^2b+3ab^2-b^3
(a-b)^2=a^2-2ab+b^2
(a+b)^2=a^2+2ab+b^2