1.Tính
a) \(\frac{1}{2}\)+\(\frac{1}{4}\)+\(\frac{1}{8}\)+\(\frac{1}{16}\)+\(\frac{1}{32}\)+\(\frac{1}{64}\)+\(\frac{1}{128}\)+\(\frac{1}{256}\)
b) \(\frac{1}{3}\)+\(\frac{1}{9}\)+\(\frac{1}{27}\)+\(\frac{1}{81}\)+\(\frac{1}{243}\)+\(\frac{1}{729}\)
c) \(\frac{1}{2}\)+\(\frac{1}{4}\)+\(\frac{1}{8}\)\(\frac{1}{16}\)+\(\frac{1}{32}\)+\(\frac{1}{64}\)