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11 tháng 11 2017

b) 2003 - | x - 2003 | = x

=> 2003 - x = | x - 2003 |

=> \(2003-x=\orbr{\begin{cases}x-2003\\2003-x\end{cases}}\)

\(\Rightarrow x=\orbr{\begin{cases}2003-x+2003\\2003-2003+x\end{cases}}\)

\(\Rightarrow x=\orbr{\begin{cases}4006-x\\0+x=x\end{cases}}\)

\(\Rightarrow x=4006-x\)

\(\Rightarrow4006=2x\Rightarrow x=4006:2=2003\)

c) Ta có : \(\left|2x-3\right|\ge0;\left|2x+4\right|\ge0\)

\(\Rightarrow\left|2x-3\right|+\left|2x+4\right|=3-2x+4+2x\)

\(=3+4=7\)

Thay \(\left|2x-3\right|=7\)

\(\Rightarrow2x-3=\orbr{\begin{cases}7\\-7\end{cases}}\Rightarrow2x=\orbr{\begin{cases}10\\-4\end{cases}}\Rightarrow x=\orbr{\begin{cases}5\\-2\end{cases}}\)

Thay \(\left|2x+4\right|=7\)

\(\Rightarrow2x+4=\orbr{\begin{cases}7\\-7\end{cases}}\Rightarrow2x=\orbr{\begin{cases}3\\-11\end{cases}}\Rightarrow x=\orbr{\begin{cases}\frac{3}{2}\\\frac{-11}{2}\end{cases}}\)

Vậy \(x\in\left(5;-2;\frac{3}{2};\frac{-11}{2}\right)\)

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

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

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

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

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

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

17 tháng 9 2016

a.|x-1/2|,|y+3/2|,|7-5/2| đều lớn hơn hoặc bằng 0

=>không tìm thấy x,y

b

11 tháng 7 2016

a)  \(\Leftrightarrow\frac{x+7}{2003}+1+\frac{x+4}{2006}+1-\frac{x-1}{2011}-1-\frac{x-5}{2015}-1=0\)

     \(\Leftrightarrow\frac{x+2010}{2003}+\frac{x+2010}{2006}-\frac{x+2010}{2011}-\frac{x+2010}{2015}=0\)

     \(\Leftrightarrow\left(x+2010\right)\left(\frac{1}{2003}+\frac{1}{2006}-\frac{1}{2011}-\frac{1}{2015}\right)=0\)

     \(\Leftrightarrow x+2010=0\) ( vì 1/2003  +  1/2006  --  1/2011  -- 1/2015   \(\ne\)0)

    \(\Leftrightarrow x=-2010\)

câu b làm tương tự (có gì không hiểu hỏi mk nha) >v<

13 tháng 9 2016

Theo bài ra , ta có : 

\(\frac{4}{5}\times\frac{5+\frac{5}{17}+\frac{5}{19}+\frac{5}{2003}}{4+\frac{4}{17}+\frac{4}{19}+\frac{4}{2003}}\)

\(=\frac{4}{5}\times\frac{5\left(\frac{1}{17}+\frac{1}{19}+\frac{1}{2003}\right)}{4\left(\frac{1}{17}+\frac{1}{19}+\frac{1}{2003}\right)}\)

\(=\frac{4}{5}\times\frac{5}{4}\)

\(=1\)

Chúc bạn học tốt

26 tháng 2 2021

\(\frac{4}{5}.\frac{5+\frac{5}{17}+\frac{5}{19}+\frac{5}{2003}}{4+\frac{4}{17}+\frac{4}{19}+\frac{4}{2003}}=\frac{4}{5}.\frac{5\left(1+\frac{1}{17}+\frac{1}{19}+\frac{1}{2003}\right)}{4\left(1+\frac{1}{17}+\frac{1}{19}+\frac{1}{2003}\right)}=\frac{4}{5}.\frac{5}{4}=1\)

1 tháng 5 2018

x=1,281236109

x=1,281236109

chú bn hok tốt

28 tháng 5 2015

x = -1/2 hoặc 1/3

x= 1

x= chưa ra

x= 2/5 hoặc -4/5

 

27 tháng 2 2020

a, Ta có : \(\frac{x+1}{3}+\frac{3\left(2x+1\right)}{4}=\frac{2x+3\left(x+1\right)}{6}+\frac{7+12x}{12}\)

=> \(\frac{4\left(x+1\right)}{12}+\frac{9\left(2x+1\right)}{12}=\frac{2\left(2x+3\left(x+1\right)\right)}{12}+\frac{7+12x}{12}\)

=> \(4\left(x+1\right)+9\left(2x+1\right)=2\left(2x+3\left(x+1\right)\right)+7+12x\)

=> \(4\left(x+1\right)+9\left(2x+1\right)=2\left(2x+3x+3\right)+7+12x\)

=> \(4x+4+18x+9=4x+6x+6+7+12x\)

=> \(4x+18x-12x-6x-4x=6+7-4-9\)

=> \(0x=0\) ( Luôn đúng với mọi x )

Vậy phương trình có vô số nghiệm .

b, Ta có : \(\frac{2-x}{2001}-1=\frac{1-x}{2002}-\frac{x}{2003}\)

=> \(\frac{2-x}{2001}+1=\frac{1-x}{2002}+1-\frac{x}{2003}+1\)

=> \(\frac{2-x}{2001}+1=\frac{1-x}{2002}+1+\frac{-x}{2003}+1\)

=> \(\frac{2-x}{2001}+\frac{2001}{2001}=\frac{1-x}{2002}+\frac{2002}{2002}+\frac{-x}{2003}+\frac{2003}{2003}\)

=> \(\frac{2003-x}{2001}=\frac{2003-x}{2002}+\frac{2003-x}{2003}\)

=> \(\frac{2003-x}{2001}-\frac{2003-x}{2002}-\frac{2003-x}{2003}=0\)

=> \(\left(2003-x\right)\left(\frac{1}{2001}-\frac{1}{2002}-\frac{1}{2003}\right)=0\)

=> \(2003-x=0\)

=> \(x=2003\)

Vậy phương trình có tập nghiệm là \(S=\left\{2003\right\}\)

4 tháng 6 2015

a,(5/8/17+-4/17):x+33/182=4/11

=5/4/17:x+33/182=4/11

5/4/17:x=4/11-33/182

5/4/17:x=365/2002

x=5/4/17:365/2002

x=28/4438/6205

b,-1/5/27-(3x-7/9)^3=-24/27

(3x-7/9)^3=-1/5/27--24/27

(3x-7/9)^3=-8/27

(3x-7/9)^3=(-2/3)^3

3x-7/9=-2/3

3x=-2/3+7/9

3x=1/9

x=1/9:3

x=1/27

 

24 tháng 4 2017

1/27 k nha!