K
Khách

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

1 tháng 9 2024

4 phần bảy nha 

đúng thì cảm ơn nha

\(3-\dfrac{5}{7}=\dfrac{21}{7}-\dfrac{5}{7}=\dfrac{21-5}{7}=\dfrac{16}{7}\)

CT
7 tháng 3 2023

Em nên gõ công thức trực quan để đề bài rõ ràng nhé

9 tháng 5 2022

a) \(\dfrac{3}{5}-\dfrac{3}{5}.\dfrac{2}{3}=\dfrac{3}{5}-\left(\dfrac{3}{5}.\dfrac{2}{3}\right)=\dfrac{3}{5}-\dfrac{2}{5}=\dfrac{1}{5}\) 

b) \(\dfrac{-7}{9}.\dfrac{11}{15}-\dfrac{4}{15}.\dfrac{-7}{9}-\dfrac{7}{9}=\dfrac{-7}{9}.\left(\dfrac{11}{15}-\dfrac{4}{15}\right)-\dfrac{7}{9}=\dfrac{-7}{9}.\dfrac{7}{15}-\dfrac{7}{9}=-\dfrac{49}{135}-\dfrac{7}{9}=-\dfrac{154}{135}\)

d) \(3\dfrac{1}{7}-\left(4\dfrac{1}{2}+5\dfrac{3}{7}\right)=\dfrac{22}{7}-\left(\dfrac{9}{2}+\dfrac{38}{7}\right)=\dfrac{22}{7}-\left(\dfrac{63}{14}+\dfrac{76}{14}\right)=\dfrac{22}{7}-\dfrac{139}{14}=\dfrac{44}{14}-\dfrac{139}{14}=-\dfrac{95}{14}\)

10 tháng 5 2020

:D

10 tháng 5 2020

a, \(\frac{3}{5}+\frac{-4}{15}=\frac{9}{15}-\frac{4}{15}=\frac{5}{15}=\frac{1}{3}\)

b, \(\frac{-1}{3}+\frac{2}{5}+\frac{2}{15}=\frac{-5}{15}+\frac{6}{15}+\frac{2}{15}=\frac{3}{15}=\frac{1}{5}\)

c, \(\frac{-3}{5}+\frac{7}{21}+\frac{-4}{5}+\frac{7}{5}=\frac{-3}{5}+\frac{1}{3}+\frac{-4}{5}+\frac{7}{5}=\left(\frac{-3}{5}+\frac{-4}{5}+\frac{7}{5}\right)+\frac{1}{3}=\frac{1}{3}\)

d, \(\frac{2}{7}+\frac{1}{9}+\frac{3}{7}+\frac{5}{9}+\frac{-5}{6}=\left(\frac{2}{7}+\frac{3}{7}\right)+\left(\frac{1}{9}+\frac{5}{9}\right)+\frac{-5}{6}=\frac{5}{7}+\frac{6}{9}+\frac{-5}{6}=\frac{90}{126}+\frac{84}{126}+\frac{-105}{126}=\frac{69}{126}=\frac{23}{42}\)

e, \(\frac{-5}{7}+\frac{3}{4}+\frac{-1}{5}+\frac{-2}{7}+\frac{1}{4}=\left(\frac{-5}{7}+\frac{-2}{7}\right)+\left(\frac{3}{4}+\frac{1}{4}\right)+\frac{-1}{5}=\left(-1\right)+1+\frac{-1}{5}=\frac{-1}{5}\)

f, \(\frac{-3}{31}+\frac{-6}{17}+\frac{1}{25}+\frac{-28}{31}+\frac{-1}{17}+\frac{-1}{5}=\left(\frac{-3}{31}+\frac{-28}{31}\right)+\left(\frac{-6}{17}+\frac{-1}{17}\right)+\left(\frac{1}{25}+\frac{-1}{5}\right)=\left(-1\right)+\frac{-7}{17}+\frac{-4}{25}=\frac{-425}{425}+\frac{-175}{425}+\frac{-68}{425}=\frac{-668}{425}\)

Chúc bn học tốt

21 tháng 4 2022

a,  \(\dfrac{-3}{5}+\dfrac{5}{7}\)

\(=\dfrac{4}{35}\)

b, \(-5+\dfrac{1}{6}\)

\(\dfrac{-29}{6}\)

c, \(\dfrac{1}{8}-\dfrac{1}{2}\)

\(\dfrac{-3}{8}\)

c, \(\dfrac{5}{12}-\dfrac{-7}{6}\)

\(\dfrac{19}{12}\)

d, \(-2.\dfrac{3}{7}\)

\(\dfrac{-6}{7}\)

10 tháng 2 2019

\(\frac{3}{7}\times\frac{1}{3}+\frac{3}{7}\times\frac{4}{3}-\frac{3}{7}\times\frac{1}{9}\)

\(\frac{3}{7}\times\left(\frac{1}{3}+\frac{4}{3}-\frac{1}{9}\right)\)

\(\frac{3}{7}\times\left(\frac{5}{3}-\frac{1}{9}\right)\)

\(\frac{3}{7}\times\left(\frac{45}{27}-\frac{3}{27}\right)\)

\(\frac{3}{7}\times\frac{14}{9}\)

\(\frac{2}{3}\)

\(\frac{7}{15}\times\frac{6}{5}+\frac{3}{5}\times\frac{6}{5}-\frac{17}{30}:\frac{5}{6}\)

\(\frac{7}{15}\times\frac{6}{5}+\frac{3}{5}\times\frac{6}{5}-\frac{17}{30}\times\frac{6}{5}\)

\(\left(\frac{7}{15}+\frac{3}{5}-\frac{17}{30}\right)\times\frac{6}{5}\)

\(\left(\frac{14}{30}+\frac{18}{30}-\frac{17}{30}\right)\times\frac{6}{5}\)

\(\frac{1}{2}\times\frac{6}{5}\)

\(\frac{3}{5}\)

Chúc bạn học tốt !!!

37×13+37×43−37×1937×13+37×43−37×19

37×(13+43−19)37×(13+43−19)

37×(53−19)37×(53−19)

37×(4527−327)37×(4527−327)

37×14937×149

23

10 tháng 2 2019

\(\frac{17}{33}.\frac{2}{5}+\frac{3}{5}.\frac{17}{33}-\frac{17}{33}\)

\(=\frac{17}{33}\times\frac{2}{5}+\frac{3}{5}\times\frac{17}{33}-\frac{17}{33}\times1\)

\(=\frac{17}{33}\times\left(\frac{2}{5}+\frac{3}{5}-1\right)\)

\(=\frac{17}{33}\times\left(1-1\right)\)

\(=\frac{17}{33}\times0=\frac{17}{33}\)

10 tháng 2 2019

 Làm he LÀM đi bạ nó lại  cồn bỏ bỏ