K
Khách

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

3 tháng 9 2016

\(3\left(2x-\frac{5}{4}\right)=\left(3-1\frac{1}{2}\right)\left(x-\frac{1}{2}\right)\)

\(\Leftrightarrow6x-\frac{15}{4}=\frac{3}{2}x+\frac{1}{12}\)

\(\Leftrightarrow\frac{9}{2}x+\frac{3}{4}=\frac{15}{4}\)

\(\Leftrightarrow\frac{9}{2}x=3\)

\(\Leftrightarrow x=\frac{2}{3}\)

3 tháng 9 2016

\(\frac{1}{3}x+\frac{2}{5}\left(x-1\right)=0\)

\(\Leftrightarrow\frac{1}{3}x+\frac{2}{5}x-\frac{2}{5}=0\)

\(\Leftrightarrow\frac{11}{15}x=\frac{2}{5}\)

\(\Leftrightarrow x=\frac{6}{11}\)

15 tháng 7 2018

\(\left(\frac{3}{4}.x-\frac{9}{16}\right).\left(\frac{1}{3}+\frac{-3}{5}:x\right)=0\)

<=> \(\hept{\begin{cases}\frac{3}{4}.x-\frac{9}{16}=0\\\frac{1}{3}-\frac{3}{5}.\frac{1}{x}=0\end{cases}}\)

<=> \(\hept{\begin{cases}x=\frac{3}{4}\\\frac{3}{5x}=\frac{1}{3}\end{cases}}\)

<=> \(\hept{\begin{cases}x=\frac{3}{4}\\x=\frac{9}{5}\end{cases}}\)

\(\left(x-\frac{1}{3}\right)\left(\frac{2}{5}+x\right)>0\)

<=> \(\hept{\begin{cases}x-\frac{1}{3}>0\\x+\frac{2}{5}>0\end{cases}}\)hoặc \(\hept{\begin{cases}x-\frac{1}{3}< 0\\x+\frac{2}{5}< 0\end{cases}}\)

<=> \(\hept{\begin{cases}x>\frac{1}{3}\\x>\frac{-2}{5}\end{cases}}\)hoặc \(\hept{\begin{cases}x< \frac{1}{3}\\x< \frac{-2}{5}\end{cases}}\)

<=>\(x>\frac{1}{3}\)hoặc \(x< \frac{-2}{5}\)

câu c tương tự nha

học tốt

4 tháng 6 2016

Tìm x, biết:

3(x+2)(x+5) +5(x+5)(x+10) +7(x+10)(x+17) =x(x+2)(x+17) (x2;5;10;17)

2(x1)(x3) +5(x3)(x8) +12(x8)(x20) 1x20 =34 (x1;3;8;20)

x+110 +2+111 x+112 =x+113 +x+114 

x1030 +x1443 +x595 +x1488 =0

4 tháng 6 2016

Trả lời luôn à bạn

8 tháng 8 2020

1) \(x-\left|1\frac{1}{6}\right|=\frac{5}{21}\)

\(\Rightarrow x-\frac{5}{21}=\left|1\frac{1}{6}\right|\)

\(\Rightarrow x-\frac{5}{21}=\frac{7}{6}\)

\(\Rightarrow x=\frac{7}{6}+\frac{5}{21}=\frac{49}{42}+\frac{10}{42}=\frac{59}{42}\)

2) \(x+\left|-1\frac{2}{3}\right|=\left|-\frac{3}{4}\right|\)

\(\Rightarrow x+\left|-1\frac{2}{3}\right|=\frac{3}{4}\)

\(\Rightarrow x-\frac{3}{4}=-\left|-1\frac{2}{3}\right|\)

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

\(\Rightarrow x-\frac{3}{4}=-\frac{5}{3}\)

\(\Rightarrow x=-\frac{5}{3}+\frac{3}{4}=-\frac{11}{12}\)

3) \(\left|x-\frac{1}{3}\right|=\frac{5}{2}\)

\(\Rightarrow\left[{}\begin{matrix}x-\frac{1}{3}=\frac{5}{2}\\x-\frac{1}{3}=-\frac{5}{2}\end{matrix}\right.\)

\(\Rightarrow\left[{}\begin{matrix}x=\frac{5}{2}+\frac{1}{3}=\frac{17}{6}\\x=-\frac{5}{2}+\frac{1}{3}=-\frac{13}{6}\end{matrix}\right.\)

4) \(\left|x+\frac{2}{3}\right|=0\)

\(\Rightarrow x+\frac{2}{3}=0\)

\(\Rightarrow x=0-\frac{2}{3}=-\frac{2}{3}\)

5) \(\left|x+2\right|=\frac{1}{3}-\frac{1}{5}\)

\(\Rightarrow\left|x+2\right|=\frac{2}{15}\)

\(\Rightarrow\left[{}\begin{matrix}x+2=\frac{2}{15}\\x+2=-\frac{2}{15}\end{matrix}\right.\)

\(\Rightarrow\left[{}\begin{matrix}x=\frac{2}{15}-2=-\frac{28}{15}\\x=-\frac{2}{15}-2=-\frac{32}{15}\end{matrix}\right.\)

6) \(\left|x-4\right|=\frac{1}{5}-\left(\frac{1}{2}-\frac{5}{4}\right)\)

\(\Rightarrow\left|x-4\right|=\frac{19}{20}\)

\(\Rightarrow\left[{}\begin{matrix}x-4=\frac{19}{20}\\x-4=-\frac{19}{20}\end{matrix}\right.\)

\(\Rightarrow\left[{}\begin{matrix}x=\frac{19}{20}+4=\frac{99}{20}\\x=-\frac{19}{20}+4=\frac{61}{20}\end{matrix}\right.\)

7) \(\left|x-\frac{5}{4}\right|=-\frac{1}{3}\)

\(\left|x-\frac{5}{4}\right|\ge0\)

=> Không có giá trị x thỏa mãn với điều kiện trên

15 tháng 6 2018

\(\frac{1}{3}x+\frac{2}{5}\left(x-1\right)=0\)

\(\Leftrightarrow\frac{1}{3}x+\frac{2}{5}x-\frac{2}{5}=0\)

\(\Leftrightarrow\frac{11}{15}x=\frac{2}{5}\)

\(\Leftrightarrow x=\frac{2}{5}\div\frac{11}{15}=\frac{2.15}{5.11}=\frac{6}{11}\)

Vậy x = 6/11 

15 tháng 6 2018

a) \(\frac{1}{3}.x+\frac{2}{5}.\left(x-1\right)=0\)

\(\frac{1}{3}.x+\frac{2}{5}.x-\frac{2}{5}=0\)

\(x.\left(\frac{1}{3}+\frac{2}{5}\right)-\frac{2}{5}=0\)

\(x.\frac{11}{15}-\frac{2}{5}=0\)

\(x.\frac{11}{15}=\frac{2}{5}\)

\(x=\frac{2}{5}:\frac{11}{15}\)

\(x=\frac{6}{11}\)

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

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

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

\(-2x-\frac{9}{2}=x+\frac{1}{5}\)

\(\Rightarrow-2x-x=\frac{1}{5}+\frac{9}{2}\)

\(-3x=\frac{47}{10}\)

\(x=\frac{47}{10}:\left(-3\right)\)

\(x=\frac{-47}{30}\)

13 tháng 4 2017

a) x = \(\frac{1}{3}\)

b) x =  \(\frac{1}{42}\)

16 tháng 8 2017

1/3 và 1/42 nha bn

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

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

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

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

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

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

24 tháng 6 2020

bạn tự làm đi tính toán thôi mà