Đặt K = 23 + 24 + 25 + ... + 2100
K = 4 + (23 + 24 + 25) + ......... + (297 + 298 + 299 + 2100)
<=> K = 4 + (8 + 16 + 32) + ... + (1.5845633e+29) +( 3.1691265e+29 ) + (6.338253e+29) + (1.2676506e+30)
<=>K = 4 + 56 + ... + (1.5845633e+29) +( 3.1691265e+29 ) + (6.338253e+29) + (1.2676506e+30)
<=>K = 60 + ... + (1.5845633e+29) +( 3.1691265e+29 ) + (6.338253e+29) + (1.2676506e+30)
<=> K = 60 + ... + 2.3768449e+30
<=> K = 2.3768449e+30 + ... + 60 + r
=> r = 1.1789905e+27
=> r = 1
Đ/s:
Ps: Không chắc đâu nhé! Nhưng dù sao giúp bạn là mình vui rồi!
C= 2535301200456458802993406410744
1116 là kết quả của mk
đúng ko sai
\(C=2^3+2^4+2^5+...+2^{100}\Rightarrow2C=2^4+2^5+2^6+...+2^{101}\)
\(\Rightarrow2C-C=\left(2^4+2^5+2^6+...+2^{101}\right)-\left(2^3+2^4+2^5+...+2^{100}\right)\)
\(\Rightarrow C=2^{101}-2^3\)
Ta có: \(2^{11}\equiv35\left(mod2013\right)\Leftrightarrow2^{33}\equiv35^3\equiv602\left(mod2013\right)\Leftrightarrow2^{99}\equiv281\left(mod2013\right)\)
\(\Leftrightarrow2^{101}\equiv281.4\equiv1124\left(mod2013\right)\Leftrightarrow C=2^{101}-2^3\equiv1124-2^3=1116\)(mod2013)
Vậy r=1116