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

\(\Leftrightarrow x+1+\left|x-5\right|=3x+1\)

\(\Leftrightarrow\left|x-5\right|=2x\)

\(\Leftrightarrow\left[{}\begin{matrix}x-5=2x\left(x\ge5\right)\\x-5=-2x\left(-\dfrac{1}{3}\le x< 5\right)\end{matrix}\right.\)

\(\Leftrightarrow\left[{}\begin{matrix}x=-5\left(ktm\right)\\x=\dfrac{5}{3}\left(tm\right)\end{matrix}\right.\)

\(\Rightarrow\left[{}\begin{matrix}-x-1+5-x=3x+1\left(x< -1\right)\\x+1+5-x=3x+1\left(-1\le x< 5\right)\\x+1+x-5=3x+1\left(x\ge5\right)\end{matrix}\right.\\ \Rightarrow\left[{}\begin{matrix}x=\dfrac{3}{5}\left(ktm\right)\\x=\dfrac{5}{3}\left(tm\right)\\x=-5\left(ktm\right)\end{matrix}\right.\Rightarrow x=\dfrac{5}{3}\)

a)

\(x^2-5x+4x-20=0.\)

\(x^2-x-20=0\)

\(\left(x^2-x+\frac{1}{4}\right)-20-\frac{1}{4}=0\)

\(\left(x-\frac{1}{2}\right)^2-\left(\frac{20.4+1}{4}\right)=0\)

\(\hept{\begin{cases}x-\frac{1}{2}-\left(\frac{20.4+1}{4}\right)=0\\x-\frac{1}{2}+\left(\frac{20.4+1}{4}\right)=0\end{cases}}\)

b)  \(x^2+6x-7x-42=0\)

\(x^2-x-42=0\)

\(x^2-x+\frac{1}{4}-42-\frac{1}{4}=0\)

\(\left(x-\frac{1}{2}\right)^2-\left(\frac{42.4+1}{4}\right)=0\)  " tương tự con A

\(x^3-16x=0\)

\(x\left(x^2-16\right)=0\)

\(x=0,+4,-4\)

\(x^3-16x=0\)

\(x.\left(x^2-16\right)=0\)

\(\Rightarrow\orbr{\begin{cases}x=0\\x^2-16=0\end{cases}\Leftrightarrow\orbr{\begin{cases}x=0\\x^2=16\end{cases}\Leftrightarrow}\orbr{\begin{cases}x=0\\x=\pm4\end{cases}}}\)

Vậy \(x=0\)hoặc \(x=\pm4\)

Tham khảo nhé~

a) \(\dfrac{5}{24}+x=\dfrac{7}{12}\)

<=> \(x=\dfrac{7}{12}-\dfrac{5}{24}=\dfrac{14}{24}-\dfrac{5}{24}=\dfrac{9}{24}=\dfrac{3}{8}\)

b) \(x-\dfrac{3}{4}=\dfrac{1}{2}\)

<=> \(x=\dfrac{1}{2}+\dfrac{3}{4}=\dfrac{2}{4}+\dfrac{3}{4}=\dfrac{5}{4}\)

c) bn ghi rõ đề chút

ok bạn

(2\7.x+3\7) :2 1\5-3\7=1

hai phần bảy nhân x cộng ba phần bảy chia hai một phần năm trừ 3 phần bảy bằng một

Giải:

a) \(\dfrac{5}{24}+x=\dfrac{7}{12}\) 

              \(x=\dfrac{7}{12}-\dfrac{5}{24}\) 

              \(x=\dfrac{3}{8}\) 

b) \(x-\dfrac{3}{4}=\dfrac{1}{2}\) 

            \(x=\dfrac{1}{2}+\dfrac{3}{4}\) 

            \(x=\dfrac{5}{4}\) 

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

           \(\left(\dfrac{2}{7}.x+\dfrac{3}{7}\right):\dfrac{11}{5}=1+\dfrac{3}{7}\) 

           \(\left(\dfrac{2}{7}.x+\dfrac{3}{7}\right):\dfrac{11}{5}=\dfrac{10}{7}\) 

                        \(\dfrac{2}{7}.x+\dfrac{3}{7}=\dfrac{10}{7}.\dfrac{11}{5}\) 

                        \(\dfrac{2}{7}.x+\dfrac{3}{7}=\dfrac{22}{7}\)           

                                \(\dfrac{2}{7}.x=\dfrac{22}{7}-\dfrac{3}{7}\) 

                                \(\dfrac{2}{7}.x=\dfrac{19}{7}\) 

                                    \(x=\dfrac{19}{7}:\dfrac{2}{7}\) 

                                    \(x=\dfrac{19}{2}\)

mk chịu mấy bài này thui

mk mới lp 6 à xl bn nha

\(\left(5\cdot\left(x^2-3x+1\right)+x\cdot\left(1-5x\right)\right)-\left(x-2\right)=0\)

\(7-15x=0\)

\(-15x=-7\)

\(x=\frac{7}{15}=0.467\)

\(b,\)câu b dài quá nên mik lười, vậy mik ghi kết quả thôi nhé

\(x=\frac{2}{19}=0.105\)

\(c,\)câu c cũng vậy mik ghi kết quả thôi nhé bn

\(x=-\frac{6}{11}=-0.545\)

0,44 x (\(x+x\times\) 5 - \(\dfrac{23}{55}\)) + \(\dfrac{3}{14}\) x 2,24 = 1

 0,44 x (\(x+x\times\)5 - \(\dfrac{23}{55}\)) + 0,48 = 1

 0,44 x (\(x+x\times\) 5 - \(\dfrac{23}{55}\)) = 1 - 0,48

0,44 x (\(x+x\times5\) - \(\dfrac{23}{55}\)) = 0,52

           \(x+x\times5\) - \(\dfrac{23}{55}\) = 0,52 : 0,44

          \(x\) x (1 + 5) -\(\dfrac{23}{55}\)  = \(\dfrac{13}{11}\)

         \(x\) x 6 - \(\dfrac{66}{10}\) = \(\dfrac{13}{11}\) + \(\dfrac{23}{55}\)

         \(x\) x 6 = \(\dfrac{65}{55}\) + \(\dfrac{23}{55}\)

          \(x\times\) 6 = \(\dfrac{8}{5}\)

         \(x\) x 6 = \(\dfrac{8}{5}\)  : 6

          \(x\)      = \(\dfrac{4}{15}\)

Vậy \(x=\dfrac{4}{15}\)

mk đang cần gấp nha

Ta có : 3/19= 12/7x
           <=> 21x=108
             <=> x= 36/7
Chúc bn hc tốt

-21/-343=-12/7x

<=>-21*7x=-343*(-12)

<=>7x=196

=>x=28

1/7x-x=5²¹:5¹⁹+3.2²-7⁰

6x=5²+3.4-1

6x=25+12-1

6x=25+11

6x=36

x=36:6

x=3

2/7x-2x=6¹⁷:6¹⁵+44:11

5x=6²+4

5x=36+4

5x=40

x=40:5

x=8

3/6x+x=5¹¹:5⁹+3

7x=5²+3

7x=25+3

7x=28

x=28:7

x=4

a)  7x - x = 5²¹: 5¹⁹ + 3.2² - 7⁰

         6x  =    5²      + 3. 4 - 1

         6x  =    25       + 12 - 1

         6x =           37        -  1

         6x =                 36

          x  =  36 : 6

          x = 6

b) 7x - 2x = 6¹⁷ : 6¹⁵ + 44:11

       5x     =    6²       + 4

        5x     =  36        +4 

        5x      = 40

        x        = 40 :5

        x        = 8

c) 6x + x = 5¹¹ : 5⁹ + 3

         7x  =    5²     +3

          7x  =  25      +3

           7x  =    28

            x   = 28 : 7

             x  = 4

Bạn ơi, 36 chia 6 bằng 3 thì đúng sao được

Lời giải:

$\frac{3}{8}+(x-\frac{5}{24}):\frac{1}{2}=1$

$(x-\frac{5}{24}):\frac{1}{2}=1-\frac{3}{8}=\frac{5}{8}$

$x-\frac{5}{24}=\frac{5}{8}\times \frac{1}{2}=\frac{5}{16}$

$x=\frac{5}{16}+\frac{5}{24}=\frac{25}{48}$