Question

[Lưu Hà Giang]

1\(\frac{1}{3}\)x    1\(\frac{1}{8}\)x   1\(\frac{1}{15}\)x    1\(\frac{1}{24}\)x ...... x  1\(\frac{1}{99}\)

Ai nhanh mk tick cho

Answer 1

[Lê Thị Mỹ Hằng]

\(1\frac{1}{3}\)x \(1\frac{1}{8}\)x  \(1\frac{1}{15}\)x .......x \(1\frac{1}{99}\)= \(\frac{4}{3}\)x \(\frac{9}{8}\)x\(\frac{16}{15}\)x..........x \(\frac{100}{99}\)

=\(\frac{2.2}{1.3}\)x\(\frac{3.3}{2.4}\)x\(\frac{4.4}{3.5}\)x.......x \(\frac{10.10}{9.11}\)= \(\frac{2.3.4....10}{1.2.3.....9}\)x \(\frac{2.3.4....10}{3.4.5....11}\)

= \(\frac{10}{1}\)x\(\frac{2}{11}\)=\(\frac{20}{11}\)

Answer 2

[Lê Châu Anh]

4/3 x 9/8 x16/15 x ..... x 100/99

=2x2/1x3 x 3x3/2x4 x 4x4/3x5 x ... x 10x10/9x11

=2x3x4x....x10/1x2x3x..x9 x 2x3x4x...x10/3x4x5x...x11

=10 x 2/11=20/11