Question

tính 1 1/3x1 1/8x1 1/5x1 1/24x......x1 1/99

mik cần gấp

 

Answer 1

=\(\dfrac{4}{3}+\dfrac{9}{8}+\dfrac{16}{15}+...+\dfrac{100}{99}\)

=\(\frac{2.2}{1.3}\)+\(\frac{3.3}{2.4}\)+.....+\(\frac{10.10}{9.11}\)

=\(\frac{2.3......10}{1.2.3.....9}\)+\(\frac{2.3.4....10}{3.4.5......11}\)

=\(10+\dfrac{2}{11}\)

=\(10\frac{2}{11}\)