Tim X .
Cau 1 : x : ( \(\frac{1}{1\times3}\) + \(\frac{1}{3\times5}\) + ...... + \(\frac{1}{101\times103}\)) = 1
Cau 2 : (\(\frac{1}{1\times2}\) + \(\frac{1}{2\times3}\) + \(\frac{1}{3\times4}\) + ......... + \(\frac{1}{11\times12}\) ) \(\times\) X = 2
cac ban giup minh nha. Minh dang can gap