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14 tháng 12 2021

\(\Rightarrow\dfrac{5}{7}-x=-\dfrac{1}{5}\Rightarrow x=\dfrac{32}{35}\)

12 tháng 1 2018

2, \(\Rightarrow\left\{{}\begin{matrix}\\\dfrac{5}{4}x-\dfrac{7}{2}=0\\\dfrac{5}{8}x+\dfrac{3}{5}=0\\\end{matrix}\right.\)

\(\Rightarrow\left\{{}\begin{matrix}x=\dfrac{14}{5}\\\\x=\dfrac{-24}{25}\\\end{matrix}\right.\)

22 tháng 9 2017

Câu 1 :

\(\dfrac{5}{7}\)+ \(\dfrac{2}{3}\). x =\(\dfrac{3}{10}\)

=> \(\dfrac{2}{3}\).x = \(\dfrac{3}{10}\) - \(\dfrac{5}{7}\)

=> \(\dfrac{2}{3}\). x = \(\dfrac{-29}{70}\)

=> x = \(\dfrac{-29}{70}\): \(\dfrac{2}{3}\)

=> x = \(\dfrac{-87}{140}\)

22 tháng 9 2017

1. \(\dfrac{5}{7}+\dfrac{2}{3}.x=\dfrac{3}{10}\)

<=>\(\dfrac{2}{3}.x=\dfrac{3}{10}-\dfrac{5}{7}=-\dfrac{29}{70}\)

<=>\(x=-\dfrac{29}{70}:\dfrac{2}{3}=-\dfrac{87}{140}\)

Vậy x=\(-\dfrac{87}{140}\)

2.\(\left(x-\dfrac{1}{2}\right):\dfrac{1}{3}+\dfrac{5}{7}=9\dfrac{5}{7}\)

\(< =>\left(x-\dfrac{1}{2}\right):\dfrac{1}{3}=9\dfrac{5}{7}-\dfrac{5}{7}=9\)

\(< =>x-\dfrac{1}{2}=9.\dfrac{1}{3}=3\\ < =>x=\dfrac{1}{2}+3=\dfrac{7}{2}\)

Vậy x=\(\dfrac{7}{2}\)

21 tháng 11 2022

1: =>1/3:x=3/5-2/3=9/15-10/15=-1/15

=>x=-1/3:1/15=5

2: \(\Leftrightarrow x\cdot\dfrac{2}{3}-3=\dfrac{2}{5}\cdot\left(-10\right)=-4\)

=>x*2/3=-1

=>x=-3/2

3: \(\Leftrightarrow\dfrac{8}{3}:x=\dfrac{25}{12}:\dfrac{-3}{50}=\dfrac{25}{12}\cdot\dfrac{-50}{3}\)

hay x=-48/625

9: =>x=-2*3/1,5=-4

8: =>2/3:x=5/2:-3/10=5/2*(-10)/3=-50/6=-25/3

=>x=-2/3:25/3=-2/3*3/25=-2/25

2 tháng 8 2017

Hoàng Ngọc Anh bài này nè bn giúp mk nha!!! ngày mai mk phải nộp bài rùi =.=

2 tháng 8 2017

a) \(\Rightarrow\dfrac{\dfrac{7}{2}x+\dfrac{59}{24}}{\dfrac{13}{30}}=\dfrac{137}{52}\)

\(\Rightarrow\left(\dfrac{7}{2}x+\dfrac{59}{24}\right).52=\dfrac{13}{30}.137\)

\(\Rightarrow182x+\dfrac{767}{6}=\dfrac{1781}{30}\)

\(\Rightarrow x=\dfrac{-79}{210}\)

b) Tương tự câu a)

2 tháng 8 2017

Giải:

a) \(\dfrac{\left(x+\dfrac{3}{4}\right).\dfrac{7}{2}-\dfrac{1}{6}}{-\left(\dfrac{4}{5}+\dfrac{1}{3}\right).\dfrac{1}{2}+1}=2\dfrac{33}{52}\)

\(\Leftrightarrow\dfrac{\left(x+\dfrac{3}{4}\right).\dfrac{7}{2}-\dfrac{1}{6}}{-\dfrac{17}{15}.\dfrac{1}{2}+1}=\dfrac{137}{52}\)

\(\Leftrightarrow\dfrac{\left(x+\dfrac{3}{4}\right).\dfrac{7}{2}-\dfrac{1}{6}}{\dfrac{13}{30}}=\dfrac{137}{52}\)

\(\Leftrightarrow\left(x+\dfrac{3}{4}\right).\dfrac{7}{2}-\dfrac{1}{6}=\dfrac{137}{52}.\dfrac{13}{30}\)

\(\Leftrightarrow\left(x+\dfrac{3}{4}\right).\dfrac{7}{2}-\dfrac{1}{6}=\dfrac{137}{120}\)

\(\Leftrightarrow\left(x+\dfrac{3}{4}\right).\dfrac{7}{2}=\dfrac{137}{120}+\dfrac{1}{6}\)

\(\Leftrightarrow\left(x+\dfrac{3}{4}\right).\dfrac{7}{2}=\dfrac{157}{120}\)

\(\Leftrightarrow x+\dfrac{3}{4}=\dfrac{157}{120}:\dfrac{7}{2}\)

\(\Leftrightarrow x+\dfrac{3}{4}=\dfrac{157}{420}\)

\(\Leftrightarrow x=\dfrac{157}{420}-\dfrac{3}{4}\)

\(\Leftrightarrow x=-\dfrac{79}{210}\)

Vậy \(x=-\dfrac{79}{210}\).

b) \(\dfrac{\left(5-\dfrac{2}{7}\right).\dfrac{7}{9}.\dfrac{3}{5}}{\left(3x-\dfrac{5}{6}\right):\dfrac{1}{7}}=5\dfrac{5}{21}\)

\(\Leftrightarrow\dfrac{\left(5-\dfrac{2}{7}\right).\dfrac{7}{15}}{\left(3x-\dfrac{5}{6}\right):\dfrac{1}{7}}=\dfrac{110}{21}\)

\(\Leftrightarrow\dfrac{\dfrac{33}{7}.\dfrac{7}{15}}{\left(3x-\dfrac{5}{6}\right):\dfrac{1}{7}}=\dfrac{110}{21}\)

\(\Leftrightarrow\dfrac{\dfrac{11}{5}}{\left(3x-\dfrac{5}{6}\right):\dfrac{1}{7}}=\dfrac{110}{21}\)

\(\Leftrightarrow\left(3x-\dfrac{5}{6}\right):\dfrac{1}{7}=\dfrac{11}{5}:\dfrac{110}{21}\)

\(\Leftrightarrow\left(3x-\dfrac{5}{6}\right):\dfrac{1}{7}=\dfrac{21}{50}\)

\(\Leftrightarrow3x-\dfrac{5}{6}=\dfrac{21}{50}.\dfrac{1}{7}\)

\(\Leftrightarrow3x-\dfrac{5}{6}=\dfrac{3}{50}\)

\(\Leftrightarrow3x=\dfrac{3}{50}+\dfrac{5}{6}\)

\(\Leftrightarrow3x=\dfrac{67}{75}\)

\(\Leftrightarrow x=\dfrac{67}{75}:3\)

\(\Leftrightarrow x=\dfrac{67}{225}\)

Vậy \(x=\dfrac{67}{225}\).

Chúc bạn học tốt!

2 tháng 8 2017

CÁC BẠN GIÚP MK NHA!!!

NGÀY MAI MK NỘP BÀI RỒI

AI TRẢ LỜI NHANH NHẤT

CHÍNH XÁC NHẤT VÀ RÕ RÀNG

THÌ MK TICK CHO NHA!!!

NHỚ TRẢ LỜI NHANH GIÙM MK NHAok

5 tháng 7 2017

chắc h có mấy thành cay r nên ko làm bn lên mạng tải phẩn mêm có cánh iair đó :D

5 tháng 7 2017

@Đoàn Đức Hiếu

26 tháng 8 2018

3. Từ \(\dfrac{x-2}{27}=\dfrac{3}{x-2}\Rightarrow\left(x-2\right)^2=81\)

\(\Rightarrow\left(x-2\right)^2=\left(\pm9\right)^2\\ \Rightarrow\left[{}\begin{matrix}x-2=-9\\x-2=9\end{matrix}\right.\Rightarrow\left[{}\begin{matrix}x=-7\\x=11\end{matrix}\right.\)

Vậy x = -7 hoặc x = 11

4. Từ \(\dfrac{2x+5}{9-2x}=\dfrac{2}{5}\)

\(\Rightarrow5\left(2x+5\right)=2\left(9-2x\right)\\ \Leftrightarrow10x+25=18-4x\\ \Leftrightarrow14x=-7\\ \Rightarrow x=-\dfrac{1}{2}\)

5. Từ \(\dfrac{x-7}{x+8}=\dfrac{x-8}{x+9}\)

\(\Rightarrow\left(x-7\right)\left(x+9\right)=\left(x-8\right)\left(x+8\right)\\ \Leftrightarrow x^2+2x-63=x^2-64\\ \Leftrightarrow2x=-1\\ \Rightarrow x=-\dfrac{1}{2}\)

2 tháng 5 2017

Tìm x:

a) \(\left(-1\dfrac{1}{5}+x\right):\left(-3\dfrac{3}{5}\right)=-\dfrac{7}{4}+\dfrac{1}{4}:\dfrac{1}{8}\)

\(\left(-1\dfrac{1}{5}+x\right):\left(-3\dfrac{3}{5}\right)=\dfrac{1}{4}\)

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

\(-1\dfrac{1}{5}+x=\dfrac{-9}{10}\)

\(\Rightarrow x=\dfrac{3}{10}\)

b) \(\dfrac{5}{7}+\dfrac{2}{3}x=\dfrac{3}{10}\)

\(\dfrac{2}{3}x=\dfrac{3}{10}-\dfrac{5}{7}\)

\(\dfrac{2}{3}x=\dfrac{-29}{70}\)

\(\Rightarrow x=\dfrac{-87}{140}\)

c) \(\dfrac{-22}{15}x+\dfrac{1}{3}=\left|\dfrac{-2}{3}+\dfrac{1}{5}\right|\)

\(-\dfrac{22}{15}x+\dfrac{1}{3}=\dfrac{7}{15}\)

\(\dfrac{-22}{15}x=\dfrac{4}{15}-\dfrac{1}{3}\)

\(\dfrac{-22}{15}x=\dfrac{2}{15}\)

\(\Rightarrow x=\dfrac{-1}{11}\)

2 tháng 5 2017

thank hihi