\(2P=24\left(5^2+1\right)\left(5^4+1\right)\left(5^8+1\right)\left(5^{16}+1\right)=\left(5^2-1\right)\left(5^2+1\right)\left(5^4+1\right)\left(5^8+1\right)\left(5^{16}+1\right)=\left(5^4-1\right)\left(5^4+1\right)\left(5^8+1\right)\left(5^{16}+1\right)=\left(5^8-1\right)\left(5^8+1\right)\left(5^{16}+1\right)=\left(5^{16}-1\right)\left(5^{16}+1\right)=5^{32}-1\Rightarrow P=\frac{5^{32}-1}{2}\)
chúc bạn học tốt 
\(P=12(5^2+1)(5^4+1)(5^8+1)(5^16+1)\)
\(12P=\left(5^2-1\right)\left(5^2+1\right)\left(5^4+1\right)\left(5^8+1\right)\left(5^{16}+1\right)\)
\(12P=\left(5^4-1\right)\left(5^4+1\right)\left(5^8+1\right)\left(5^{16}+1\right)\)
12P=...
12P=\(\left(5^{16}-1\right)\left(5^{16}+1\right)\)
12P=\(5^{32}-1\)
=>P=\(\dfrac{244140624}{12}=203450552\)
Chú ý rằng 12=24/2=(5^2-1)/2.Vậy
12(5^2+1)(5^4+1)(5^8+1)(5^16+1)=
(5^2-1)(5^2+1)(5^4+1)(5^8+1)(5^16+1)/2...
(5^4-1)(5^4+1)(5^8+1)(5^16+1)/2=
(5^8-1)(5^8+1)(5^16+1)/2=
(5^16-1)(5^16+1)/2=(5^32-1)/2.
Tất cả các bước đều áp dụng hằng đẳng thức (a+b)(a-b)=a^2-b^2.
