\(\frac{6}{7}+\frac{5}{9}+\frac{8}{7}...">
K
Khách

Hãy nhập câu hỏi của bạn vào đây, nếu là tài khoản VIP, bạn sẽ được ưu tiên trả lời.

27 tháng 4 2017

a,    6/7+5/9+8/7-2/9=(6/7+8/7)+(5/9-2/9)=14/7+3/9=2+1/3=7/3

b, 5+7/3=22/3

27 tháng 4 2017

a/ \(\frac{6}{7}+\frac{5}{9}+\frac{8}{7}-\frac{2}{9}\)

\(\left(\frac{6}{7}+\frac{8}{7}\right)+\left(\frac{5}{9}-\frac{2}{9}\right)\)

=  \(2+\frac{1}{3}\)

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

b/ 5+\(2\frac{1}{3}\)

= 5 + \(\frac{7}{3}\)

\(\frac{22}{3}\)

25 tháng 7 2021

a, 3 \(\frac{14}{19}\)\(\frac{13}{17}\)\(\frac{35}{43}\)+ 6\(\frac{5}{19}\)\(\frac{8}{43}\)\(\left(3\frac{14}{19}+6\frac{5}{19}\right)+\left(\frac{35}{43}+\frac{8}{43}\right)+\frac{13}{17}=\)\(9+1+\frac{13}{17}=8+\frac{13}{17}=8\frac{13}{17}\)

b, \(\frac{-5}{7}.\frac{2}{11}+\frac{-5}{7}.\frac{9}{11}+1\frac{5}{7}\)\(=\frac{-5}{7}\left(\frac{2}{11}+\frac{9}{11}\right)+1\frac{5}{7}\)\(=\frac{-5}{7}.1+1\frac{5}{7}\)\(=\frac{-5}{7}+\frac{12}{7}=\frac{7}{7}=1\)

Chúc bn học tốt

\(3\frac{14}{19}+\frac{13}{17}+\frac{35}{43}+6\frac{5}{19}+\frac{8}{43}\)

\(=\left(3\frac{14}{19}+6\frac{5}{19}\right)+\left(\frac{35}{43}+\frac{8}{43}\right)+\frac{13}{17}\)

\(=10+1+\frac{13}{17}=11+\frac{13}{17}=11\frac{13}{17}\)

1 tháng 4 2017

bài 1 :\(\frac{3}{8}-\frac{1}{5}+\frac{3}{40}=\frac{1}{4}\)

\(\frac{9}{7}\cdot\left(\frac{3}{7}-\frac{1}{2}\right)=-\frac{9}{98}\)

\(-\frac{3}{7}\cdot\frac{5}{9}+\frac{4}{9}\cdot-\frac{3}{7}\cdot\frac{3}{7}=\left(\frac{4}{9}+\frac{5}{9}-1\right)\cdot-\frac{3}{7}=-1\cdot-\frac{3}{7}=\frac{3}{7}\)

bài 2: \(x+\frac{2}{5}=\frac{9}{10}\)

\(x=\frac{9}{10}-\frac{2}{5}\)

\(x=\frac{1}{2}\)

1 tháng 4 2017

x = \(\frac{9}{10}\)\(\frac{2}{5}\)

x =\(\frac{9}{10}\) - \(\frac{4}{10}\)

x = \(\frac{5}{10}\) = \(\frac{1}{2}\)

Vậy x = \(\frac{1}{2}\)

ai thấy tớ đúng thì ủng hộ nha

tui đang âm

16 tháng 2 2015

c. N= \(\frac{-5}{7}\cdot\left(\frac{2}{11}+\frac{9}{11}\right)+\frac{12}{7}\)

N=1

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

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

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

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

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

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

26 tháng 7 2019

a) \(\left(-0,75+\frac{1}{2}\right):\frac{4}{3}\)

\(=\frac{-1}{4}:\frac{4}{3}\)

\(=\frac{-3}{16}\)

b) \(\frac{5}{9}.\frac{2}{7}+\frac{5}{9}.\frac{5}{7}-\frac{8}{3}\)

\(=\frac{5}{9}.\left(\frac{2}{7}+\frac{5}{7}\right)-\frac{8}{3}\)

\(=\frac{5}{9}.1-\frac{8}{3}\)

\(=\frac{-19}{9}\)

c)  \(7,5.1\frac{3}{4}-6\frac{2}{5}\)

\(=\frac{15}{2}.\frac{7}{4}-\frac{32}{5}\)

\(=\frac{269}{40}\)