\(A=2^{100}-2^{99}+2^{98}-2^{97}+...+2^2-2=2^{99}\left(2-1\right)+2^{97}\left(2-1\right)+...+2\left(2-1\right)=\left(2^{99}+2^{97}+...+2\right)\)
A = 2100 - 299 + 298 - 297 + ... + 22 - 2
2A = 2101 - 2100 + 299 - 298 + ... + 23 - 22
2A + A = (2101 - 2100 + 299 - 298 + ... + 23 - 22) + ( 2100 - 299 + 298 - 297 + .. + 22 - 2)
3A = 2101 - 2
A = \(\frac{2^{101}-2}{3}\)
A = 2100 - 299 + 298 - 297 + ... + 22 - 2
2A = 2101 - 2100 + 299 - 298 + ... + 23 - 22
2A + A = (2101 - 2100 + 299 - 298 + ... + 23 - 22) + ( 2100 - 299 + 298 - 297 + .. + 22 - 2)
3A = 2101 - 2
A = $\frac{2^{101}-2}{3}$