A=2^100-2^99+2^98-...+2^2-2
=>2A=2^101-2^100+2^99-....+2^3-2^2
=>2A+A=2^101-2
=>3A=2^101-2
=>A=(2^101-2)/3
2A = 2101 - 2100 + 299 - ..... - 22 + 2
2A + A = (-2100 + 2100) + .... + (-22 + 22) + 2101 - 2
3A = 2101 - 2
Vậy A = \(\frac{2^{101}-2}{3}\)
A=2^100-2^99+2^98-...+2^2-2
=>2A=2^101-2^100+2^99-...+2^3-2^2
=>2A+a=2^101-2
=>3A=2^101-2
=>a=(2^101-2)/3
A=2100-299+........+22-2
2A=2.(2100-299+.........+22)
2A=2101-2100+.....+22
2A+A=(2101-2100+.....+22)+(2100-299+....+22+2)
3A=2101+2