a)\(\frac{1}{2}\)-\(\frac{1}{3\cdot7}\)-\(\frac{1}{7\cdot11}\)-\(\frac{1}{11\cdot15}\)-\(\frac{1}{15\cdot19}\)-\(\frac{1}{19\cdot23}\)-\(\frac{1}{23\cdot27}\)
b) 1-\(\frac{1}{5\cdot10}\)-\(\frac{1}{10\cdot15}\)-\(\frac{1}{15\cdot20}\)-...-\(\frac{1}{95\cdot100}\)