\(\frac{10+x}{17+x}=\frac{3}{4}\)

 b) 

K
Khách

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5 tháng 6 2017

Ta có :\(\frac{40+x}{77-x}=\frac{6}{7}\)

\(\Rightarrow7\left(40+x\right)=\left(77-x\right).6\)

\(\Leftrightarrow280+7x=462-6x\)

\(\Rightarrow7x+6x=462-280\)

\(\Rightarrow13x=182\)

\(\Rightarrow x=14\)

5 tháng 6 2017

Ta có : \(\frac{10+x}{17+x}=\frac{3}{4}\)

\(\Rightarrow4\left(10+x\right)=3\left(17+x\right)\)

\(\Leftrightarrow40+4x=51+3x\)

\(\Rightarrow4x-3x=51-40\)

\(\Rightarrow x=11\)

17 tháng 2 2016

\(1-\frac{10+x}{17+x}=1-\frac{3}{4}\)

\(\frac{7}{17+x}=\frac{1}{4}\)

\(\frac{7}{17+x}=\frac{7}{28}\Rightarrow17+x=28\)

\(x=28-17=11\)

17 tháng 2 2016

Con Phan b thi Sao?

27 tháng 4 2019

\(x-40\%x=3,6\)

\(\Rightarrow100\%x-40\%x=3,6\)

\(\Rightarrow60\%x=3,6\)

\(\Rightarrow\frac{60}{100}x=3,6\)

\(\Rightarrow x=6\)

27 tháng 4 2019

\(3\frac{2}{7}x-\frac{1}{3}=-2\frac{3}{4}\)

\(\Rightarrow\frac{23}{7}x-\frac{1}{3}=-\frac{11}{4}\)

\(\Rightarrow\frac{23}{7}x=-\frac{33}{12}+\frac{4}{12}\)

\(\Rightarrow\frac{23}{7}x=\frac{29}{12}\)

\(\Rightarrow x=\frac{29}{12}:\frac{23}{7}=\frac{203}{276}\)

19 tháng 4 2017

a) x = 1

19 tháng 4 2017

a.X=\(\frac{25}{7}\)

7 tháng 2 2017

a) (\(6\frac{2}{7}.x+\frac{3}{7}\))=-1.\(\frac{11}{5}+\frac{3}{7}\)

(\(6\frac{2}{7}.x+\frac{3}{7}\))=\(\frac{-62}{35}\)

\(\frac{44}{7}.x\)=\(\frac{-62}{35}-\frac{3}{7}\)

\(\frac{44}{7}.x=\frac{-77}{35}\)

x=\(\frac{-77}{35}:\frac{44}{7}\)=\(\frac{539}{1540}\)

6 tháng 6 2016

a) (1/2(2/− 2x0

\(\Rightarrow\left[\begin{array}{nghiempt}x+\frac{1}{2}=0\\\frac{2}{3}-2x=0\end{array}\right.\)

\(\Rightarrow\left[\begin{array}{nghiempt}x=-\frac{1}{2}\\2x=\frac{2}{3}\end{array}\right.\)

\(\Rightarrow\left[\begin{array}{nghiempt}x=-\frac{1}{2}\\x=\frac{1}{3}\end{array}\right.\)

b) \(\left(x.6\frac{2}{7}+\frac{3}{7}\right).2\frac{1}{5}-\frac{3}{7}=-2\)

\(\Rightarrow\left(x.\frac{44}{7}+\frac{3}{7}\right).\frac{11}{5}=-2+\frac{3}{7}\)

\(\Rightarrow\left(x.\frac{44}{7}+\frac{3}{7}\right).\frac{11}{5}=-\frac{11}{7}\)

\(\Rightarrow x.\frac{44}{7}+\frac{3}{7}=-\frac{11}{7}:\frac{11}{5}=-\frac{11}{7}.\frac{5}{11}\)

\(\Rightarrow x.\frac{44}{7}+\frac{3}{7}=-\frac{5}{7}\)

\(\Rightarrow x.\frac{44}{7}=-\frac{5}{7}-\frac{3}{7}\)

\(\Rightarrow x.\frac{44}{7}=-\frac{8}{7}\)

\(\Rightarrow x=-\frac{8}{7}:\frac{44}{7}=-\frac{8}{7}.\frac{7}{44}\)

\(\Rightarrow x=-\frac{2}{11}\)

6 tháng 6 2016

c) \(x.3\frac{1}{4}+\left(-\frac{7}{6}\right).x-1\frac{2}{3}=\frac{5}{12}\)

\(\Rightarrow x\left(3\frac{1}{4}-\frac{7}{6}\right)=\frac{5}{12}+\frac{5}{3}\)

\(\Rightarrow x\left(\frac{13}{4}-\frac{7}{6}\right)=\frac{25}{12}\)

\(\Rightarrow x.\frac{25}{12}=\frac{25}{12}\)

\(\Rightarrow x=\frac{25}{12}:\frac{25}{12}\)

\(\Rightarrow x=1\)

d) \(5\frac{8}{17}:x+\left(-\frac{4}{17}\right):x+3\frac{1}{7}:17\frac{1}{3}=\frac{4}{11}\)

\(\Rightarrow\left(5\frac{8}{17}-\frac{4}{17}\right):x+\frac{22}{7}:\frac{52}{3}=\frac{4}{11}\)

\(\Rightarrow5\frac{4}{17}:x+\frac{33}{182}=\frac{4}{11}\)

\(\Rightarrow\frac{89}{17}:x=\frac{4}{11}-\frac{33}{182}\)

\(\Rightarrow\frac{89}{17}:x=\frac{365}{2002}\)

\(\Rightarrow x=\frac{89}{17}:\frac{365}{2002}\)

\(\Rightarrow x\approx28,7\) (số hơi lẻ)

e) \(\frac{17}{2}-\left|2x-\frac{3}{4}\right|=-\frac{7}{4}\)

\(\Rightarrow\left|2x-\frac{3}{4}\right|=\frac{17}{2}+\frac{7}{4}\)

\(\Rightarrow\left|2x-\frac{3}{4}\right|=\frac{41}{4}\)

\(\Rightarrow\left[\begin{array}{nghiempt}2x-\frac{3}{4}=\frac{41}{4}\\2x-\frac{3}{4}=-\frac{41}{4}\end{array}\right.\)

\(\Rightarrow\left[\begin{array}{nghiempt}2x=11\\2x=-\frac{19}{2}\end{array}\right.\)

\(\Rightarrow\left[\begin{array}{nghiempt}x=\frac{11}{2}\\x=-\frac{19}{4}\end{array}\right.\)

29 tháng 3 2018

\(\frac{x+2}{17}+\frac{x+4}{15}+\frac{x+6}{13}=\frac{x+8}{11}+\frac{x+10}{9}+\frac{x+12}{7}\)

\(\Rightarrow\left(\frac{x+2}{17}+1\right)+\left(\frac{x+4}{15}+1\right)+\left(\frac{x+6}{13}+1\right)-\left(\frac{x+8}{11}+1\right)-\left(\frac{x+10}{9}+1\right)-\left(\frac{x+12}{7}+1\right)=0\)

\(\Rightarrow\frac{x+19}{17}+\frac{x+19}{15}+\frac{x+19}{13}-\frac{x+19}{11}-\frac{x+19}{10}-\frac{x+19}{7}=0\)

\(\Rightarrow\left(x+19\right)(\frac{1}{17}+\frac{1}{15}+\frac{1}{13}-\frac{1}{11}-\frac{1}{9}-\frac{1}{7})\)

\(\Rightarrow x+19=0\)\(\left(Vì\frac{1}{17}+\frac{1}{15}+\frac{1}{13}-\frac{1}{11}-\frac{1}{9}-\frac{1}{7}\ne0\right)\)

\(\Rightarrow x=-19\)

28 tháng 3 2018

Ta có : \(\frac{x+2}{17}+\frac{x+4}{15}+\frac{x+6}{13}=\frac{x+8}{11}+\frac{x+10}{9}+\frac{x+12}{7}\)

\(\Rightarrow\left(\frac{x+2}{17}+1\right)+\left(\frac{x+4}{15}+1\right)+\left(\frac{x+6}{13}+1\right)=\left(\frac{x+8}{11}+1\right)+\left(\frac{x+10}{9}+1\right)+\left(\frac{x+12}{7}+1\right)\)

\(\Rightarrow\frac{x+19}{17}+\frac{x+19}{15}+\frac{x+19}{13}-\frac{x+19}{11}-\frac{x+19}{9}-\frac{x+19}{7}=0\)

\(\Rightarrow\left(x+19\right)\left(\frac{1}{17}+\frac{1}{15}+\frac{1}{13}-\frac{1}{11}-\frac{1}{9}-\frac{1}{7}\right)=0\)

\(\Rightarrow x+19=0\Rightarrow x=-19\)

6 tháng 5 2021

-xx=-2x4

-xx=-8

xx=8

x2=8

x= căn bâc của 8

8 tháng 2 2024

a; \(\dfrac{-x}{4}\) = \(\dfrac{-2}{x}\)

    -\(x.x\) = -2.4

    -\(x^2\) = -8

      \(x^2\) = 8

      \(\left[{}\begin{matrix}x=-\sqrt{8}\\x=\sqrt{8}\end{matrix}\right.\)

Vậy \(x\in\) {-\(\sqrt{8}\)\(\sqrt{8}\)}

      

21 tháng 2 2016

b) <=> 4(10+x) = 3(17+x) 

40+4x=51+3x 

4x-3x=51-40 

x=11 

c) <=> 7.(40+x) = 6 .(17+x) 

280+7x =102 + 6x

7x-6x=102-280 

x=-178 

21 tháng 2 2016

a)  7/x=x/28

=)7*28=x*x

=)196=x^2

=)14^2=x^2

= )x=14

k cho mih di roi mih giai tiep cho nha

18 tháng 4 2017

a)\(\frac{-2}{3}.x+\frac{1}{5}=\frac{3}{10}\)

\(\frac{-2}{3}x=\frac{3}{10}-\frac{1}{5}=\frac{1}{10}\)

\(\frac{-2}{3}x=\frac{1}{10}\)

\(x=\frac{1}{10}\div\frac{-2}{3}=\frac{-3}{20}\)

b)\(\left(50\%.x+2\frac{1}{4}\right).\frac{-2}{3}=\frac{17}{6}\)

\(50\%.x+2\frac{1}{4}=\frac{17}{6}\div\frac{-2}{3}\)\(=\frac{-17}{4}\)

\(50\%.x+2\frac{1}{4}=\frac{-17}{4}\)

\(50\%.x=\frac{-17}{4}-2\frac{1}{4}=\frac{-17}{4}-\frac{9}{4}=\frac{-26}{4}=\frac{-13}{2}\)

\(50\%.x=\frac{-13}{2}\)

\(x=\frac{-13}{2}\div50\%=-13\)

18 tháng 4 2017

\(\frac{-2}{3}\)\(\hept{\begin{cases}.\\.\\.\end{cases}ads}\)