\(\frac{-3}{7}\)x\(\frac{5}{12}\)+\(\fra...">
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14 tháng 5 2019

\(-\frac{5}{28}\)

15 tháng 5 2019

\(\frac{-3}{7}.\frac{5}{12}+\frac{3}{7}.\frac{7}{12}+\frac{-3}{12}\)

\(=\frac{3}{7}.\frac{-5}{12}+\frac{3}{7}.\frac{7}{12}+\frac{-1}{4}\)

\(=\frac{3}{7}.\left(\frac{-5}{12}+\frac{7}{12}\right)+\frac{-1}{4}\)

\(=\frac{3}{7}.\frac{2}{12}+\frac{-1}{4}\)

\(=\frac{3}{7}.\frac{1}{6}+\frac{-1}{4}\)

\(=\frac{3}{42}+\frac{-1}{4}\)

\(=\frac{1}{14}-\frac{1}{4}\)

\(=\frac{4}{56}-\frac{14}{56}\)

\(=\frac{-10}{56}=\frac{-5}{28}\)

8 tháng 7 2020

Trả lời

\(A=\frac{7}{12}+\frac{5}{12}\div6-\frac{11}{36}\)

\(A=\frac{7}{12}+\frac{5}{12}\times\frac{1}{6}-\frac{11}{36}\)

\(A=\frac{7}{12}+\frac{5}{72}-\frac{11}{36}\)

\(A=\frac{25}{72}\)

    \(B=12\frac{1}{3}-\frac{5}{7}\div\left(24-23\frac{5}{7}\right)\)

\(B=\frac{37}{3}-\frac{5}{7}\div\left(24-\frac{166}{7}\right)\)

\(B=\frac{37}{3}-\frac{5}{7}\div\frac{2}{7}\)

\(B=\frac{37}{3}-\frac{5}{7}\times\frac{7}{2}\)

\(B=\frac{37}{3}-\frac{5}{2}\)

\(B=\frac{59}{6}\)

8 tháng 7 2020

Bài làm:

Ta có: 

\(A=\frac{7}{12}+\frac{5}{12}\div6-\frac{11}{36}\)

\(A=\frac{7}{12}+\frac{5}{72}-\frac{11}{36}\)

\(A=\frac{42+5-22}{72}=\frac{25}{72}\)

\(B=12\frac{1}{3}-\frac{5}{7}\div\left(24-23\frac{5}{7}\right)\)

\(B=\frac{37}{3}-\frac{5}{7}\div\left(24-23-\frac{5}{7}\right)\)

\(B=\frac{37}{3}-\frac{5}{7}\div\left(1-\frac{5}{7}\right)\)

\(B=\frac{37}{3}-\frac{5}{7}+1\)

\(B=\frac{265}{21}\)

18 tháng 4 2021

a

\(5\frac{4}{7}:x+=13\)

\(\frac{39}{7}:x=13\)

\(x=\frac{39}{7}:13\)

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

18 tháng 4 2021

\(\frac{4}{7}x=\frac{9}{8}-0,125\)

\(\frac{4}{7}x=1\)

\(x=1:\frac{4}{7}\)

\(x=\frac{7}{4}=1\frac{3}{4}\)

8 tháng 7 2020

\(A=\frac{7}{12}+\frac{5}{12}:6-\frac{1}{36}\)

\(=\frac{7}{12}+\frac{5}{72}-\frac{11}{36}\)

\(=\frac{42}{72}+\frac{5}{72}-\frac{22}{72}\)

\(=\frac{25}{72}\)

8 tháng 7 2020

A=25/72\

B=59/6

5 tháng 6 2020

Bài làm

a) \(-\frac{3}{7}+\frac{3}{4}:\frac{3}{14}\)

\(-\frac{3}{7}+\frac{3}{4}.\frac{14}{3}\)

\(-\frac{3}{7}+\frac{7}{2}\)

\(=-\frac{7}{14}+\frac{49}{14}\)

\(=\frac{42}{14}=3\)

b) \(5-\frac{7}{39}:\frac{7}{13}+\frac{8}{9}:4\)

\(=5=\frac{7}{39}.\frac{13}{7}+\frac{8}{9}.\frac{1}{4}\)

\(=5-\frac{1}{3}+\frac{2}{9}\)

\(=\frac{45}{9}-\frac{3}{9}+\frac{2}{9}\)

\(=\frac{44}{9}\)

c) \(\left(\frac{5}{12}:\frac{11}{6}+\frac{5}{12}:\frac{11}{5}\right)-\frac{-7}{12}\)

\(=\left(\frac{5}{12}.\frac{6}{11}+\frac{5}{12}.\frac{5}{11}\right)+\frac{7}{12}\)

\(=\left[\frac{5}{12}\left(\frac{6}{11}+\frac{5}{11}\right)\right]+\frac{7}{12}\)

\(=\frac{5}{12}+\frac{7}{12}\)

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

d) \(-\frac{5}{9}+\frac{14}{9}\left(\frac{3}{4}-\frac{2}{5}\right):49\)

\(=-\frac{5}{9}+\frac{14}{9}\left(\frac{15}{20}-\frac{8}{20}\right):49\)

\(=-\frac{5}{9}+\frac{14}{9}.\frac{7}{20}.\frac{1}{49}\)

\(=-\frac{5}{9}+\frac{7}{9}.\frac{7}{10}.\frac{1}{7.7}\)

\(=-\frac{5}{9}+\frac{1}{90}\)

\(=-\frac{50}{90}+\frac{1}{90}=-\frac{49}{90}\)

17 tháng 5 2018

a) \(\frac{x}{3}-\frac{1}{4}=\frac{-5}{6}\)

\(\Rightarrow\frac{x}{3}=\frac{-5}{6}+\frac{1}{4}\)

\(\Rightarrow\frac{x}{3}=\frac{-7}{12}\)

\(\Rightarrow x=\frac{\left(-7\right).3}{12}\)

\(\Rightarrow x=\frac{-7}{4}\)

Vậy x = \(\frac{-7}{4}\)

b) \(\frac{x+3}{15}=\frac{1}{3}\)

\(\Rightarrow\left(x+3\right).3=15\)

\(\Rightarrow x+3=15:3\)

\(\Rightarrow x+3=5\)

\(\Rightarrow x=5-3\)

\(\Rightarrow x=2\)

Vậy x = 2

c) \(\frac{x-12}{4}=\frac{1}{2}\)

\(\Rightarrow\left(x-12\right).2=4\)

\(\Rightarrow x-12=4:2\)

\(\Rightarrow x-12=2\)

\(\Rightarrow x=2+12\)

\(\Rightarrow x=14\)

Vậy x = 14

d) \(\frac{25}{9}-\frac{12}{13}x=\frac{7}{9}\)

\(\Rightarrow\frac{12}{13}x=\frac{25}{9}-\frac{7}{9}\)

\(\Rightarrow\frac{12}{13}x=2\)

\(\Rightarrow x=2:\frac{12}{13}\)

\(\Rightarrow x=\frac{13}{6}\)

Vậy x = \(\frac{13}{6}\)

_Chúc bạn học tốt_

17 tháng 5 2018

a)\(\frac{x}{3}-\frac{1}{4}=-\frac{5}{6}\)

\(\frac{x}{3}=-\frac{5}{6}+\frac{1}{4}\)

\(\frac{x}{3}=-\frac{7}{12}\)

\(x=-\frac{7}{12}\times3\)

\(\Rightarrow x=-\frac{7}{4}\)

b) \(\frac{x+3}{15}=\frac{1}{3}\)

\(\frac{x+3}{15\div5}=\frac{1}{3}\)

\(\Rightarrow x=5-3\)

\(\Rightarrow x=2\)

c) \(\frac{x-12}{4}=\frac{1}{2}\)

\(\frac{x-12}{4\div2}=\frac{1}{2}\)

\(x=12+2\)

\(\Rightarrow x=14\)

d) tự làm nhé cũng dễ mà

3 tháng 3 2019

a, \(A=\frac{19}{24}-\frac{1}{2}-\frac{1}{3}-\frac{7}{24}=(\frac{19}{24}-\frac{7}{24})-\frac{1}{2}-\frac{1}{3}\)

\(=\frac{12}{24}-\frac{1}{2}-\frac{1}{3}\)

\(=\frac{1}{2}-\frac{1}{2}-\frac{1}{3}=0-\frac{1}{3}=-\frac{1}{3}\)

\(B=\frac{7}{12}+\frac{5}{6}+\frac{1}{4}-\frac{3}{7}-\frac{5}{12}=(\frac{7}{12}-\frac{5}{12})+\frac{5}{6}+\frac{1}{4}-\frac{3}{7}\)

\(=\frac{1}{6}+\frac{5}{6}+\frac{1}{4}-\frac{3}{7}\)

\(=1+\frac{1}{4}-\frac{3}{7}=\frac{23}{28}\)

b, Thay thế A = \(-\frac{1}{3}\)và B = \(\frac{23}{28}\)ta có :

\(-\frac{1}{3}-x=\frac{23}{28}\)

\(\Rightarrow x=-\frac{1}{3}-\frac{23}{28}=-\frac{28}{84}-\frac{69}{84}=\frac{-28-69}{84}=\frac{-97}{84}\)