#)Giải :

\(1\frac{1}{3}\times1\frac{1}{8}\times1\frac{1}{15}\times...\times1\frac{1}{9800}\)

\(=\frac{4}{3}\times\frac{9}{8}\times\frac{16}{15}\times...\times\frac{9801}{9800}\)

\(=\frac{2.2}{1.3}\times\frac{3.3}{2.4}\times\frac{4.4}{3.5}\times...\times\frac{99.99}{98.100}\)

\(=\frac{2.3.4.....99}{1.2.3.....98}\times\frac{2.3.4.....99}{3.4.5.....100}\)

\(=99\times\frac{2}{100}=\frac{198}{100}=\frac{99}{50}\)

\(=\frac{4}{3}\times\frac{9}{8}\times\frac{16}{15}\times...\times\frac{9801}{9800}\)

\(=\frac{2.2}{1.3}\times\frac{3.3}{2.4}\times\frac{4.4}{3.5}\times...\times\frac{99.99}{98.100}\)

\(=\frac{2.3.4.5.....99}{1.2.3.4....98}\times\frac{2.3.4.5.....99}{3.4.5.6.....100}\)

\(=\frac{99}{1}\times\frac{2}{100}\)

\(=\frac{99}{50}\)

mình trả lời cho bạn nè !

=4/3x9/8x16/15x...x10000/9999

=(4x9x16x...x10000)/(3x8x15x...x9999)

=(2x2x3x3x4x4x...x100x100)/(1x3x2x4x3x5x...x99x101)

=(2x2x3x3x4x4x...x100x100)/(1x2x3x3x4x4x5x5x...x100x100x101)

=2/101

cách làm của mình giống Công Chúa Giá Băng nha!K cho mình đi,mình có 200 nick luôn!

a) x + 1/15 = 1/3 - 1/4 = 4/12 - 3/12 = 1/12.

=> x = 1/12 - 1/15 = 5/60 - 4/60 = 1/60.

b) x - 5/12 = 1/3 + 1/4 = 4/12 + 3/12 = 7/12.

=> x = 7/12 + 5/12 = 1

c) x x 2/7 = 3/4 x 4/15 = 1/5

=> x = 1/5 : 2/7 = 1/5 x 7/2 = 7/10

d) x : 3/8 = 4/3 : 3/6 = 4/3 x 2 = 8/3

=> x = 8/3 x 3/8 = 1

Ta có: \(P=1\frac13\times1\frac18\times1\frac{1}{15}\times\ldots\times1\frac{1}{80}\times1\frac{1}{99}\)

\(=\frac43\times\frac98\times\frac{16}{15}\times\ldots\times\frac{81}{80}\times\frac{100}{99}\)

\(=\frac{2\times2}{1\times3}\times\frac{3\times3}{2\times4}\times\ldots\times\frac{10\times10}{9\times11}\)

\(=\frac{2\times3\times\ldots\times10}{1\times2\times\ldots\times9}\times\frac{2\times3\times\ldots\times10}{3\times4\times\ldots\times11}=\frac{10}{1}\times\frac{2}{11}=\frac{20}{11}\)