S = 1 + 3 + 32 + 33 + ... + 3100
3S = 3 + 32 + 33 + 34 + ... + 3101
3S - S = ( 3 + 32 + 33 + 34 + ... + 3101 ) - ( 1 + 3 + 32 + 33 + ... + 3100 )
2S = 3101 - 1
S = 3101 - 1 / 2
S=1+3+32+33+.....+399+3100
=>3S=3+32+33+34+.....+3100+3101
=>3S - S =2S=(3+32+33+34+....+3101) - (1+3+32+33+....+3100)=(3-1)+(32-32)+(33-33)+.....+(3100-3100)+3101=2+3101
=>S=(2+3101)/2
Ta có: S = 1 + 3 +32 +33 +... + 3100
=> 3S = 3 + 32 + 33 +...+3101
=> 3S - S = (3 + 32 + 33 +...+ 3101) - (1 + 3 + 32 +...+3100)
=> 2S = 3101 - 1
\(\Rightarrow S=\frac{3^{101}-1}{2}\)
\(3S=3+3^2+...+3^{101}\)
\(2S=3^{101}-1\)
\(\Rightarrow S=\frac{3^{101}-1}{2}\)
S=1+3.(3+32+33+........+3100+3101-3101)
S=
