=> \(2A=2+2^2+2^3+2^4+...+2^{100}+2^{101}\)
= \(2A-A=\left(2+2^2+2^3+2^4+...+2^{100}+2^{101}\right)-\left(1+2+2^2+2^3+..+2^{99}+2^{100}\right)\)
=> A = \(2^{101}-1\)
yên tâm đúng nhé, tui học dạng này rùi
C = 1 + 2 + 22 + 23 + 24 + ... + 2100
2C= (1 + 2 + 22 + 23 + 24 + ... + 2100) x2
2C =2+22+23+24+....+2101
2C-C= ( 2+22+23+24+....+2101) - (1 + 2 + 22 + 23 + 24 +.......+2100)
C= 2101 - 1