Vom folosi formula :
(a-b)(a+b) = a² - b²
[tex]\it (2+1)(2^2+1)(2^4+1)(2^8+1)(2^{16}+1) =
\\ \\
= (2-1)(2+1)(2^2+1)(2^4+1)(2^8+1)(2^{16}+1) =
\\ \\
(2^2-1)(2^2+1)(2^4+1)(2^8+1)(2^{16}+1) =
\\ \\
=(2^4-1)(2^4+1)(2^8+1)(2^{16}+1) = (2^8-1)(2^8+1)(2^{16}+1) =
\\ \\
= (2^{16}-1)(2^{16}+1) = 2^{32}-1[/tex]
Expresia din enunț devine:
[tex]\it 2^{32} -1+2^{32} = -1[/tex]