Số số hạng dãy trên có là:

( 100 - 1 ) : 3 + 1 = 34 ( số hạng )

Tổng là:

( 100 + 1 ) x 34 : 2 = 1717

=> 1717: x = 17

x = 1717 : 17

= 101

Ta có: (1+4+7+....+100) : x=17

1717 : x=17

x=1717:17

x=101

a, \(\frac{5}{11}\times\frac{7}{25}+\frac{15}{11}\times\frac{1}{5}\)

\(=\frac{5}{11}\times\frac{7}{25}+\frac{5}{11}\times\frac{3}{5}\)

\(=\frac{5}{11}\times\left(\frac{7}{25}+\frac{3}{5}\right)\)

\(=\frac{5}{11}\times\frac{22}{25}\)

\(=\frac{2}{5}\)

b, \(\frac{3}{7}\times\frac{25}{19}-\frac{1}{7}\times\frac{18}{19}\)

\(=\frac{1}{7}\times\frac{75}{19}-\frac{1}{7}\times\frac{18}{19}\)

\(=\frac{1}{7}\times\left(\frac{75}{19}-\frac{18}{19}\right)\)

\(=\frac{1}{7}\times3\)

\(=\frac{3}{7}\)

hahahahahahahahahahahahahahahahahahahahahahahahahahahahahahehehehehehehehehehehehehehehehehehehahahahehahehahe

=1 PHAN 12 NHA

KIK MÌNH NHA

Làm từng cái nhé: \(\frac{25}{32}\times\frac{8}{50}=\frac{1}{4}\times\frac{1}{2}=\frac{1}{8}\)

Tiếp: \(\frac{1}{8}\times\frac{4}{3}=\frac{1}{2}\times\frac{1}{3}=\frac{1}{6}\)

Tiếp: \(\frac{5}{10}=\frac{1}{2}\)

Còn lại: \(\frac{1}{2}\times\frac{1}{6}=\frac{1}{12}\)

\(\frac{25}{32}\cdot\frac{8}{50}.\frac{4}{3}.\frac{5}{10}=\frac{1}{12}\)

\(\frac{25}{32}\times\frac{8}{50}\times\frac{4}{3}\times\frac{5}{10}\)

\(=\frac{5\times5\times8\times4\times5}{8\times4\times5\times5\times2\times3\times5\times2}\)

\(=\frac{1}{12}\)

k mk nha

thank you very much

\(x+\frac{2}{5}=1-\frac{1}{6}\)

\(x+\frac{2}{5}=\frac{5}{6}\)

\(x=\frac{5}{6}-\frac{2}{5}=\frac{13}{30}\)

\(x=\frac{13}{30}\)

\(\frac{7}{8}-x=\frac{2}{3}+\frac{1}{8}\)

\(\frac{7}{8}-x=\frac{19}{24}\)

\(x=\frac{7}{8}-\frac{19}{24}=\frac{1}{12}\)

\(x=\frac{1}{12}\)

0.00102605144

\(\frac{4}{5}\)

4

x = 0 ???

Đây là toán lớp 4?!