a) \(\dfrac{17}{24}\times\dfrac{3}{51}=\dfrac{51}{1224}=\dfrac{1}{24}\)

b) \(\dfrac{6}{7}\div\dfrac{24}{49}-\dfrac{1}{24}\)

\(=\dfrac{7}{4}-\dfrac{1}{24}=\dfrac{41}{24}\)

a) \(\dfrac{17}{24}\)x\(\dfrac{3}{51}=\dfrac{51}{1224}=\dfrac{1}{24}\)

b) \(\dfrac{6}{7}:\dfrac{24}{49}-\dfrac{1}{24}=\dfrac{7}{4}-\dfrac{1}{24}=\dfrac{41}{24}\)

\(\frac{7.25-49}{7.24-24}=\frac{175-49}{168-24}=\frac{126}{144}=\frac{7}{8}\)

Ta có: \(\frac{7\times25-49}{7\times24-24}\) 

=\(\frac{7\times25-7\times2}{7\times24-24\times1}\) 

= \(\frac{7\left(25-2\right)}{24\left(7-1\right)}\) 

=\(\frac{7\times23}{24\times6}\)

= \(\frac{161}{96}\)

Mai Thanh Tâm

Sai

bội vs mũ mà kêu toán lớp 1 

ko trả lời thì im cái con aname nguyễn kia

a, \(\dfrac{10}{17}\) + \(\dfrac{5}{-13}\) - \(\dfrac{11}{25}\) + \(\dfrac{7}{17}\) - \(\dfrac{8}{13}\)

= ( \(\dfrac{10}{17}\) + \(\dfrac{7}{17}\)) - ( \(\dfrac{5}{13}\) + \(\dfrac{8}{13}\)) - \(\dfrac{11}{25}\)

= \(\dfrac{17}{17}\) - \(\dfrac{13}{13}\) - \(\dfrac{11}{25}\)

= 1 - 1 - \(\dfrac{11}{25}\)

= - \(\dfrac{11}{25}\)

b, 0,3 - \(\dfrac{93}{7}\) - 70% - \(\dfrac{4}{7}\)

= 0,3 - 0,7 - ( \(\dfrac{93}{7}+\dfrac{4}{7}\))

= - 0,4 - \(\dfrac{97}{7}\)
= - \(\dfrac{2}{5}\) - \(\dfrac{97}{7}\)

= - \(\dfrac{499}{35}\)

c, \(\dfrac{1}{8}\) + \(\dfrac{1}{24}\) + \(\dfrac{1}{48}\)+ ...+ \(\dfrac{1}{2400}\)

= \(\dfrac{1}{2\times4}\)  +\(\dfrac{1}{4\times6}\) + \(\dfrac{1}{6\times8}\) +...+ \(\dfrac{1}{48\times50}\)

= \(\dfrac{1}{2}\) \(\times\) ( \(\dfrac{2}{2\times4}\) +\(\dfrac{2}{4\times6}\)+ \(\dfrac{2}{6\times8}\) +...+ \(\dfrac{2}{48\times50}\))

= \(\dfrac{1}{2}\) \(\times\) ( \(\dfrac{1}{2}\) - \(\dfrac{1}{4}\) + \(\dfrac{1}{4}\) - \(\dfrac{1}{6}\) + \(\dfrac{1}{6}\) - \(\dfrac{1}{8}\) +...+ \(\dfrac{1}{48}\) - \(\dfrac{1}{50}\))

= \(\dfrac{1}{2}\) \(\times\) ( \(\dfrac{1}{2}\) - \(\dfrac{1}{50}\))

= \(\dfrac{1}{2}\) \(\times\) \(\dfrac{12}{25}\)

= \(\dfrac{6}{25}\)

              6 x 7 =  42                                        49 : 7 =  7

              7 x 4 =  28                                        24 : 6 = 4

7x 25-49=175-49= 126

7-24+21=-17+21=4

đáp án =0 

5/24-84-49/3

=-2011/24-49/3

=-801/8

a: \(x-\dfrac{10}{3}=\dfrac{7}{15}\cdot\dfrac{3}{5}\)

=>\(x-\dfrac{10}{3}=\dfrac{21}{75}=\dfrac{7}{25}\)

=>\(x=\dfrac{7}{25}+\dfrac{10}{3}=\dfrac{21+250}{75}=\dfrac{271}{75}\)

b: \(x+\dfrac{3}{22}=\dfrac{27}{121}\cdot\dfrac{9}{11}\)

=>\(x+\dfrac{3}{22}=\dfrac{243}{1331}\)

=>\(x=\dfrac{243}{1331}-\dfrac{3}{22}=\dfrac{123}{2662}\)

c: \(\dfrac{8}{23}\cdot\dfrac{46}{24}-x=\dfrac{1}{3}\)

=>\(\dfrac{8}{24}\cdot\dfrac{46}{23}-x=\dfrac{1}{3}\)

=>\(\dfrac{2}{3}-x=\dfrac{1}{3}\)

=>\(x=\dfrac{2}{3}-\dfrac{1}{3}=\dfrac{1}{3}\)

d: \(1-x=\dfrac{49}{65}\cdot\dfrac{5}{7}\)

=>\(1-x=\dfrac{49}{7}\cdot\dfrac{5}{65}=\dfrac{7}{13}\)

=>\(x=1-\dfrac{7}{13}=\dfrac{6}{13}\)

\(1,8\cdot1\frac{1}{24}-\left(25-24\frac{17}{49}\right):\frac{16}{49}\)

\(=1,8\cdot\frac{25}{24}-\left(25-24+\frac{17}{49}\right):\frac{16}{49}\)

\(=\frac{15}{8}-\frac{66}{49}:\frac{16}{49}\)

\(=\frac{15}{8}-\frac{33}{8}=\frac{-9}{4}\)