K
Khách

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

23 tháng 4 2017

\(\dfrac{4}{7}.\dfrac{89}{5}-\dfrac{4}{5}.\dfrac{82}{7}\)

\(=\dfrac{4}{7}.\dfrac{89}{5}-\dfrac{4}{7}.\dfrac{82}{5}\)

\(=\dfrac{4}{7}.\left(\dfrac{89}{5}-\dfrac{82}{5}\right)\)

\(=\dfrac{4}{7}.\dfrac{7}{5}\)

\(=\dfrac{4}{5}\)

\(\dfrac{5}{7}.\dfrac{-4}{19}+\dfrac{-15}{7}.\dfrac{5}{19}\)

\(=\dfrac{5}{7}.\dfrac{-4}{19}+\dfrac{5}{7}.\dfrac{-15}{19}\)

\(=\dfrac{5}{7}.\left(\dfrac{-4}{19}+\dfrac{-15}{19}\right)\)

\(=\dfrac{5}{7}.\left(-1\right)\)

\(=\dfrac{-5}{7}\)

23 tháng 4 2017

- cảm ơn cậu nha khocroi

25 tháng 4 2017

\(-2\dfrac{1}{4}.\)\(\left(3\dfrac{5}{12}-1\dfrac{2}{9}\right)\)

=\(\dfrac{-9}{4}\).\(\left(\dfrac{41}{12}-\dfrac{11}{9}\right)\)

=\(\dfrac{-9}{4}.\dfrac{41}{12}-\dfrac{-9}{4}.\dfrac{11}{9}\)

=\(\dfrac{-123}{16}-\dfrac{-11}{4}\)

=\(\dfrac{-123}{16}-\dfrac{-44}{16}\)

=\(\dfrac{-79}{16}\)

25 tháng 4 2017

\(\left(-25\%+0,75+\dfrac{7}{12}\right)\div\left(-2\dfrac{1}{8}\right)\)

=\(\left(\dfrac{-1}{4}+\dfrac{3}{4}+\dfrac{7}{12}\right)\div\left(\dfrac{-17}{8}\right)\)

=\(\left(\dfrac{-3}{12}+\dfrac{9}{12}+\dfrac{7}{12}\right).\dfrac{-8}{17}\)

=\(\dfrac{13}{12}.\dfrac{-8}{17}=\dfrac{-26}{51}\)

g: \(=\dfrac{-3}{4}-\dfrac{1}{4}+\dfrac{5}{7}+\dfrac{2}{7}+\dfrac{3}{5}=\dfrac{3}{5}\)

h: \(=\dfrac{7}{19}\left(\dfrac{8}{11}+\dfrac{3}{11}\right)-\dfrac{12}{19}=\dfrac{7}{19}-\dfrac{12}{19}=-\dfrac{5}{19}\)

i: \(=\dfrac{2013}{7}\left(19+\dfrac{5}{8}-26-\dfrac{5}{8}\right)=\dfrac{2013}{7}\cdot\left(-7\right)=-2013\)

8: \(=\dfrac{-5}{9}-\dfrac{4}{9}+\dfrac{8}{15}+\dfrac{7}{15}-\dfrac{2}{11}=\dfrac{-2}{11}\)

9: =2/7-2/5+5/7=1-2/5=3/5

10: \(=\dfrac{7}{19}\left(\dfrac{8}{11}+\dfrac{3}{11}\right)-\dfrac{12}{19}=\dfrac{-5}{19}\)

11: \(=\dfrac{-5}{7}\left(\dfrac{2}{11}+\dfrac{9}{11}\right)=\dfrac{-5}{7}\)

16 tháng 4 2022

8 = -2/11

9 = 3/5

10 = -5/19

11 = -5/7

11 = 5/13

 

 

21 tháng 4 2017

= ( 5/7 + -15/7 ) . ( -4/19 + 5/19 )

=10/7 . 1/19

=10/133

21 tháng 4 2017

sai rùi

20 tháng 4 2017

Có:

\(\dfrac{4}{7}.\dfrac{89}{5}-\dfrac{4}{5}.\dfrac{82}{7}\)

\(=\dfrac{4}{7}.\dfrac{89}{5}-\dfrac{4.82}{5.7}=\dfrac{4}{7}.\dfrac{89}{5}-\dfrac{4.82}{7.5}=\dfrac{4}{7}.\dfrac{89}{5}-\dfrac{4}{7}.\dfrac{89}{5}\)

\(=\dfrac{4}{7}.\left(\dfrac{89}{5}-\dfrac{82}{5}\right)=\dfrac{4}{7}.\dfrac{7}{5}=\dfrac{4}{5}\)

Chúc bạn học tốt!ok

20 tháng 4 2017

\(\dfrac{4}{7}\) .\(\dfrac{89}{5}\) - \(\dfrac{4}{5}\). \(\dfrac{82}{7}\)

= \(\dfrac{4.89}{7.5}\) - \(\dfrac{4}{5}\) . \(\dfrac{82}{7}\)= \(\dfrac{4}{5}\) .\(\dfrac{89}{7}\) - \(\dfrac{4}{5}\) . \(\dfrac{82}{7}\)= \(\dfrac{4}{5}\)\(\left(\dfrac{89}{7}-\dfrac{82}{7}\right)\)= \(\dfrac{4}{5}\). 1= \(\dfrac{4}{5}\)

`@` `\text {Ans}`

`\downarrow`

`j)`

`-3/4 + 2/7 + (-1)/4 + 3/5 + 5/7`

`= (-3/4 - 1/4) + (2/7 + 5/7) + 3/5`

`= -1 + 1 + 3/5`

`= 3/5`

`k)`

`-2/17 + 15/23 + (-15)/17 + 4/19 + 8/23`

`= (-2/17 - 15/17) + (15/23 + 8/23) + 4/19`

`= -1 + 1 + 4/19`

`= 4/19`

$#KDN040510$

j: =-3/4-1/4+2/7+5/7+3/5

=-1+1+3/5

=3/5

k: =-2/17-15/17+15/23+8/23+4/19

=-1+1+4/19

=4/19

29 tháng 4 2018

c,

= \(\dfrac{5}{9}.\left(\dfrac{7}{13}+\dfrac{9}{13}+\dfrac{-3}{13}\right)\)

= \(\dfrac{5}{9}.1\)

= \(\dfrac{5}{9}\)

29 tháng 4 2018

a,

= \(\dfrac{1}{3}.\left(\dfrac{4}{5}+\dfrac{6}{5}\right)+\dfrac{-4}{3}\)

= \(\dfrac{1}{3}.\dfrac{10}{5}+\dfrac{-4}{3}\)

= \(\dfrac{2}{3}+\dfrac{-4}{3}\)

= \(\dfrac{-2}{3}\)

a: =9+7=16

b: =11+3/13-2-4/7-5-3/13

=4-4/7

=28/7-4/7=24/7

c: =2/7(5+1/4-3-1/4)=2/7x2=4/7