1 . \(\frac{1}{1x2}\)+ \(\frac{1}{2x3}\)+ \(\frac{1}{3x4}\)+ ....... +\(\frac{1}{99x100}\)
2, \(\frac{2}{3x5}\)+ \(\frac{2}{5x7}\)+ \(\frac{2}{7x9}\)+ ........... + \(\frac{2}{39x41}\)
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