Dễ thế mà không làm được thì bạn nên xem lại nhé,một hai câu thì còn được chứ cả 10 câu thế kia rõ là ỷ lại rồi bạn ạ.Thân!

ừ đúng dễ mà

mk giải ở dưới được 2 câu rùi nhưng ko chắc cau 2 ~~~

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1,1/3+1/2:X= -4

         1/2:X= -4-1/3

         1/2:X= -13/3

              X=1/2 : -13/3

             X= -3/26

Giúp với

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

   => 1/2 : x = -4 - 1/3

        1/2 : x = -13/3

      => x = 1/2 : (-13/3)

          x = -3/26

2. 3x - 30%.x = -5,4

     3x - x = -18

      2x = -18

=> x = -18 : 2

     x = -9

3. x-43 = (57 - x) - 50

  => (57 - x) . (x - 43) = -50

=> 57 - x = -50 => x = 107

=> x - 43 = -50 => x = -50 + 43 = -7

4. 3/8 - 1/6x = 1/4

 => 1/6x = 3/8 - 1/4 = 1/8

=> x = 1/8 : 1/6 = 3/4

5. 2/3 + 1/3 : x = 3/5

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

=> x = 1/3 : (-1/15) = -5

6. x + 30%x = -1/3

 bó tay hihi!!!!

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

\(a,3\left(2x-3\right)+2\left(2-x\right)=-3\\ \Leftrightarrow6x-9+4-2x=-3\\ \Leftrightarrow4x=2\\ \Leftrightarrow x=\dfrac{1}{2}\\ b,x\left(5-2x\right)+2x\left(x-1\right)=13\\ \Leftrightarrow5x-2x^2+2x^2-2x=13\\ \Leftrightarrow3x=13\\ \Leftrightarrow x=\dfrac{13}{3}\\ c,5x\left(x-1\right)-\left(x+2\right)\left(5x-7\right)=6\\ \Leftrightarrow5x^2-5x-5x^2-3x+14=6\\ \Leftrightarrow-8x=-8\\ \Leftrightarrow x=1\\ d,3x\left(2x+3\right)-\left(2x+5\right)\left(3x-2\right)=8\\ \Leftrightarrow6x^2+9x-6x^2-11x+10=8\\ \Leftrightarrow-2x=-2\\ \Leftrightarrow x=1\)

\(e,2\left(5x-8\right)-3\left(4x-5\right)=4\left(3x-4\right)+11\\ \Leftrightarrow10x-16-12x+15=12x-16+11\\ \Leftrightarrow-14x=-4\\ \Leftrightarrow x=\dfrac{2}{7}\\ f,2x\left(6x-2x^2\right)+3x^2\left(x-4\right)=8\\ \Leftrightarrow12x^2-4x^3+3x^3-12x^2=8\\ \Leftrightarrow-x^3-8=0\\ \Leftrightarrow-\left(x^3+8\right)=0\\ \Leftrightarrow-\left(x+2\right)\left(x^2-2x+4\right)=0\\ \Leftrightarrow\left[{}\begin{matrix}x=-2\\x\in\varnothing\left(x^2-2x+4=\left(x-1\right)^2+3>0\right)\end{matrix}\right.\)

Bài 4:

a: Ta có: \(3\left(2x-3\right)-2\left(x-2\right)=-3\)

\(\Leftrightarrow6x-9-2x+4=-3\)

\(\Leftrightarrow4x=2\)

hay \(x=\dfrac{1}{2}\)

b: Ta có: \(x\left(5-2x\right)+2x\left(x-1\right)=13\)

\(\Leftrightarrow5x-2x^2+2x^2-2x=13\)

\(\Leftrightarrow3x=13\)

hay \(x=\dfrac{13}{3}\)

c: Ta có: \(5x\left(x-1\right)-\left(x+2\right)\left(5x-7\right)=6\)

\(\Leftrightarrow5x^2-5x-5x^2+7x-10x+14=6\)

\(\Leftrightarrow-8x=-8\)

hay x=1

a/ \(3\left(2x-3\right)+2\left(2-x\right)=-3\)

\(\Leftrightarrow6x-9+4-2x=-3\)

\(\Leftrightarrow4x=2\)

\(\Leftrightarrow x=\dfrac{1}{2}\)

Vậy: \(x=\dfrac{1}{2}\)

===========

b/ \(x\left(5-2x\right)+2x\left(x-1\right)=13\)

\(\Leftrightarrow5x-2x^2+2x^2-2x=13\)

\(\Leftrightarrow3x=13\)

\(\Leftrightarrow x=\dfrac{13}{3}\)

Vậy: \(x=\dfrac{13}{3}\)

==========

c/  \(5x\left(x-1\right)-\left(x+2\right)\left(5x-7\right)=6\)

\(\Leftrightarrow5x^2-5x-5x^2+7x-10x+14=6\)

\(\Leftrightarrow-8x=-8\)

\(\Leftrightarrow x=1\)

Vậy: \(x=1\)

==========

d/ \(3x\left(2x+3\right)-\left(2x+5\right)\left(3x-2\right)=8\)

\(\Leftrightarrow6x^2+9x-6x^2+4x-15x+10=8\)

\(\Leftrightarrow-2x=-2\)

\(\Leftrightarrow x=1\)

Vậy: \(x=1\)

==========

e/ \(2\left(5x-8\right)-3\left(4x-5\right)=4\left(3x-4\right)+11\)

\(\Leftrightarrow10x-16-12x+15=12x-16+11\)

\(\Leftrightarrow-14x=-4\)

\(\Leftrightarrow x=\dfrac{2}{7}\)

Vậy: \(x=\dfrac{2}{7}\)

==========

f/ \(2x\left(6x-2x^2\right)+3x^2\left(x-4\right)=8\)

\(\Leftrightarrow12x^2-4x^3+3x^3-12x^2=8\)

\(\Leftrightarrow-x^3=8\)

\(\Leftrightarrow x=-2\)

Vậy: \(x=-2\)

* \(6x+3-2\left(x-5\right)=30\)

\(\Rightarrow6x+3-2x+10=30\)

\(\Rightarrow4x=17\Leftrightarrow x=\frac{17}{4}\)

* \(8\left(x-\frac{1}{8}\right)-5\left(x-\frac{1}{5}\right)=10\)

\(\Rightarrow3\left(x-\frac{1}{5}\right)=10\)

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

\(\Rightarrow x=\frac{10}{3}+\frac{1}{5}=\frac{53}{15}\)

* \(13x-5-2\left(x+3\right)=1\)

\(\Rightarrow13x-5-2x-6=1\)

\(\Rightarrow11x=12\Leftrightarrow x=\frac{12}{11}\)

Dễ thế mà bạn không tự làm ak

a) \(x=\dfrac{1}{4}+\dfrac{2}{13}\)

\(x=\dfrac{13}{52}+\dfrac{8}{52}\)

⇒ \(x=\dfrac{21}{52}\)

b) \(\dfrac{x}{3}=\dfrac{2}{3}+\dfrac{-1}{7}\)

\(\dfrac{x}{3}=\dfrac{14}{21}+\dfrac{-3}{21}\)

\(\dfrac{x}{3}=\dfrac{11}{21}\)

⇒ \(x=\dfrac{11.3}{21}=\dfrac{33}{21}\)

⇒ \(x=\dfrac{11}{7}\)

c) \(\dfrac{-8}{3}+\dfrac{1}{3}< x< \dfrac{-2}{7}+\dfrac{-5}{7}\)

\(\dfrac{-17}{7}< x< -1\)

⇒ \(-17< x< -7\)

⇒ \(x\in\left\{-16;-15,....;-6\right\}\)

d) \(\dfrac{1}{6}+\dfrac{2}{5}\)

\(=\dfrac{5}{30}+\dfrac{12}{30}\)

\(=\dfrac{17}{30}\)

e) \(\dfrac{3}{5}+\dfrac{-7}{4}\)

\(=\dfrac{12}{20}+\dfrac{-35}{20}\)

\(=\dfrac{-23}{20}\)

f) \(\dfrac{4}{13}+\dfrac{-12}{30}\)

\(=\dfrac{4}{13}+\dfrac{-2}{5}\)

\(=\dfrac{20}{65}+\dfrac{-26}{65}\)

\(=\dfrac{-6}{65}\)

g) \(\dfrac{-3}{29}+\dfrac{16}{58}\)

\(=\dfrac{-6}{58}+\dfrac{16}{58}\)

\(=\dfrac{10}{58}\)

h) \(\dfrac{8}{40}+\dfrac{-36}{45}\)

\(=\dfrac{1}{5}+\dfrac{-4}{5}\)

\(=\dfrac{-3}{5}\)

j) \(\dfrac{-8}{18}+\dfrac{15}{27}\)

\(=\dfrac{-2}{9}+\dfrac{5}{9}\)

\(=\dfrac{3}{9}\)

\(=\dfrac{1}{3}\)