\(a,x-\dfrac{7}{12}x=\dfrac{5}{24}-\dfrac{3}{8}x\)

\(\Leftrightarrow\dfrac{5}{12}x+\dfrac{3}{8}x=\dfrac{5}{24}\)

\(\Leftrightarrow\dfrac{19}{24}x=\dfrac{5}{24}\Leftrightarrow x=\dfrac{5}{19}\)

Vậy x = 5/19

\(b,\left(x-\dfrac{1}{2}\right)\left(-3-\dfrac{x}{2}\right)=0\)

\(\Leftrightarrow\left[{}\begin{matrix}x-\dfrac{1}{2}=0\\-3-\dfrac{x}{2}=0\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x=\dfrac{1}{2}\\x=-6\end{matrix}\right.\)

Vậy x = 1/2 hoặc x = -6

\(c,\dfrac{x-3}{-2}=\dfrac{-8}{x-3}\)

\(\Leftrightarrow\left(x-3\right)^2=16\)

\(\Leftrightarrow\left[{}\begin{matrix}x-3=4\\x-3=-4\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x=7\\x=-1\end{matrix}\right.\)

Vậy x = 7 hoặc x = -1

a) \(x-\dfrac{3}{4}=6.\dfrac{3}{8}=\dfrac{9}{4}\)

\(\Rightarrow x=\dfrac{9}{4}+\dfrac{3}{4}=3\)

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

\(\Rightarrow x+\dfrac{1}{6}=\dfrac{3}{4}\Rightarrow x=\dfrac{3}{4}-\dfrac{1}{6}=\dfrac{9}{12}-\dfrac{2}{12}=\dfrac{7}{12}\)

Bạn xem lại đề c

Xin lỗi, bạn xem lại đề b

b) \(\dfrac{7}{8}:x=3\dfrac{1}{2}\)

\(\Rightarrow\dfrac{7}{8}:x=\dfrac{7}{2}\)

\(\Rightarrow x=\dfrac{7}{8}:\dfrac{7}{2}\)

\(\Rightarrow x=\dfrac{1}{4}\)

\(a,\dfrac{-1}{8}=\dfrac{3}{x}\\ \dfrac{3}{-24}=\dfrac{3}{x}\\ x=-24\\ b,\dfrac{x}{3}=\dfrac{3}{x}\\ x.x=3.3\\ x^2=9\\ x=\pm3\\ c,\dfrac{3}{4}.x=1\dfrac{1}{2}\\ \dfrac{3}{4}.x=\dfrac{3}{2}\\ x=\dfrac{3}{2}:\dfrac{3}{4}\\ x=2\\ d,x-\dfrac{3}{10}=\dfrac{7}{15}:\dfrac{3}{5}\\ x-\dfrac{3}{10}=\dfrac{7}{9}\\ x=\dfrac{7}{9}+\dfrac{3}{10}\\ x=\dfrac{97}{90}\\ e,\dfrac{-4}{7}-x=\dfrac{-8}{3}.\dfrac{3}{7}\\ \dfrac{-4}{7}-x=\dfrac{-8}{7}\\ x=\dfrac{-4}{7}+\dfrac{8}{7}\\ x=\dfrac{4}{7}\\ \)

f: =>x*4/7=1/5+2/3=3/15+10/15=13/15

=>x=91/60

g: =>1/3:3x=1/5-2/3=-7/15

=>3x=-5/7

=>x=-5/21

h: =>7/8x=-1/9

=>x=-1/9:7/8=-1/9*8/7=-8/63

j: =>(2,8x-50)=34

=>2,8x=84

=>x=30

1)

Ta có: \(\left(x-\frac{1}{2}\right)^3=8\Rightarrow\left(x-\frac{1}{2}\right)^3=2^3\)

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

\(\left(x-1\right)^3=\frac{8}{27}\Rightarrow\left(x-1\right)^3=\left(\frac{2}{3}\right)^3\)

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

x=5/3

a: =>(x-2)^3*[(x-2)^2-1]=0

=>(x-2)(x-3)(x-1)=0

=>\(x\in\left\{1;2;3\right\}\)

b: =>(x-3)^2*(x-3-1)=0

=>(x-3)(x-4)=0

=>x=3 hoặc x=4

c: =>\(11\cdot\dfrac{6^x}{6}+2\cdot6^x\cdot6=6^{11}\left(11+2\cdot6^2\right)\)

=>6^x(11/6+12)=6^12(11/6+12)

=>x=12

1: x=3/4-1/2=3/4-2/4=1/4

2: x-1/5=2/11

=>x=2/11+1/5=21/55

3: x-5/6=16/42-8/56

=>x-5/6=8/21-4/28=5/21

=>x=5/21+5/6=15/14

4: x/5=5/6-19/30

=>x/5=25/30-19/30=6/30=1/5

=>x=1

5: =>|x|=1/3+1/4=7/12

=>x=7/12 hoặc x=-7/12

6: x=-1/2+3/4

=>x=3/4-1/2=1/4

11: x-(-6/12)=9/48

=>x+1/2=3/16

=>x=3/16-1/2=-5/16

1)x= 1/4

2)x= 2/11+ 1/5

   x= 21/55

3)x - 5/6 = 5/21

   x         = 5/21+5/6

   x         = 15/14

4)x/5 = 5/6 + -19/30

   x:5 = 1/5

   x    = 1/5.5

   x    = 1

5) |x| - 1/4 = 6/18

    |x|           = 6/18 - 1/4

    |x|            =7/12

⇒x= 7/12 hoặc -7/12

6)x = -1/2 +3/4

   x= 1/4

7) x/15 = 3/5 + -2/3

   x:15  = -1/15

  x        = -1/15. 15

  x        = -1

8)11/8 + 13/6 = 85/x  

       85/24      = 85/x

  ⇒      x           = 24

9) x - 7/8 = 13/12

   x          = 13/12 + 7/8

   x          = 47/24

10)x - -6/15 = 4/27  

     x            = 4/27 + (-6/15)

    x             = -34/135

11) -(-6/12)+x = 9/48

                    x= 9/48 - 6/12

                    x = -5/16

12) x - 4/6 = 5/25 + -7/15

      x -4/6  =  -4/15

     x           = -4/15 + 4/6

    x             = 2/5

a) \(6.8^{x-1}+8^{x+1}=6.8^{19}+8^{21}\)

\(\Rightarrow x-1+x+1=19+21\)

\(=2x=40\)

\(\Rightarrow x=20\)

b) \(4.3^{x-1}+2.3^{x+2}=4.3^6+2.3^9\)

\(\Rightarrow x-1+x+2=6+9\)

\(\Rightarrow2x+1=15\)

\(\Rightarrow2x=14\)

\(\Rightarrow x=7\)

dùng fx gõ cho hẳn hoi

1: 7-x=8+(-7)

=>7-x=8-7=1

=>x=7-1=6

2: \(x-8=\left(-3\right)-8\)

=>x-8=-11

=>\(x=-11+8=-3\)

3: \(2-x=10-9+23\)

=>\(2-x=33-9=24\)

=>x=2-24=-22

4: \(-2-x=15\)

=>\(x=-2-15=-17\)

5: \(-7+x-8=-3-1+13\)

=>x-14=13-4=9

=>x=9+14=23

6: 100-x+7=-x+3

=>107-x=3-x

=>107=3(vô lý)

7: \(23+x=8-2x\)

=>\(x+2x=8-23\)

=>3x=-15

=>x=-15/3=-5