\(C=2+2^2+...+2^{100}\)
\(C=\left(2+2^2+2^3+2^4+2^5\right)+\left(2^5+2^6+2^7+2^9+2^{10}\right)...+\left(2^{96}+2^{97}+2^{98}+2^{99}+2^{100}\right)\)
\(C=2.\left(1+2+2^2+2^3+2^4\right)+2^5\left(1+2+2^2+2^3+2^4\right)+...+2^{96}\left(1+2+2^2+2^3+2^4\right)\)
\(C=2.31+2^5.31+...+2^{96}.31\)
\(C=31.\left(2+2^5+...+2^{96}\right)\)(VÌ TÍCH CÓ THỪA SỐ 31 NÊN CHIA HẾT CHO 31)