5xy-15y+2x-6=
=(5xy-15y)(2x-6)=
=5y(x-3) 2(x-3)=
=(5y+2)(x-3)
(10+с)²-10²=(10+с-10)(10+с+10)=с*(с+20)
(5-у)²-у²=(5-у-у)(5-у+у)=5*(5-2у)
X1 = 1/2^1 + 2^1 = 1/2 + 2 = 2,5
x2 = 1/2^2 + 2^2 = 1/4 + 4 = 4,25
x3 = 1/2^3 + 2^3 = 1/8 + 8 = 8,125
x4 = 1/2^4 + 2^4 = 1/16 + 16 = 16,0625
x5 = 1/2^5 + 2^5 = 1/32 + 32 = 32,03125