bài 1 :

x + 678 = 2813

         x  =  2813 - 678

         x  = 2135

4529 + x = 7685

            x = 7685 - 4529

            x = 3156

x - 358 = 4768

        x  = 4768 + 358

        x  =  5126

2495 - x = 698

           x = 2495 - 698 

           x = 1797

x × 23 = 3082

        x = 3082 : 23 

        x = 134

36 × x = 27612

      x =  27612 : 36 

      x = 767

x : 42 = 938

       x =  938 x 42 

       x = 39396

4080 : x = 24

           x = 4080 : 24 

           x =170

bài 2 :

a. x + 6734 = 3478 + 5782

    x + 6734 = 9260

             x    =  9260 - 6734

             x    =  2526

b. 2054 + x = 4725 - 279

    2054 + x  = 4446

                x  =  4446 - 2054

                x  = 2392

c. x - 3254 = 237 x 145

    x - 3254 = 34365

             x   =  34365 + 3254

             x   =   37619

d. 124 - x = 44658 : 54

    124 - x = 827

             x = 827 - 124 

             x = 703

Bài 3: 

a. x × 24 = 3027 + 2589

    X x 24 = 5616

            x  = 5616 : 24 

            x  = 234

b. 42 × x = 24024 - 8274

    42 x X = 15750

            X = 15750 : 42 

            X = 375

c. x : 54 = 246 ×185

    X : 54 = 45510

          X  = 45510 x 54 

          X  = 2457540

d. 134260 : x = 13230 : 54

    134260 : x = 245

                   x = 134260 : 245

                   x  = 548

đúng tick chị nhé em!!! cảm ơn em nà :3

Bn xem lại đề xem sao chứ chưa có kết quả chưa tìm đc x đâu nha

Ta có: \(x\left(x-4\right)+1=3x-5\)

\(\Leftrightarrow x^2-4x+1-3x+5=0\)

\(\Leftrightarrow\left(x-1\right)\left(x-6\right)=0\)

\(\Leftrightarrow\left[{}\begin{matrix}x=1\\x=6\end{matrix}\right.\)

x(x - 4) + 1 = 3x - 5

<=> x² - 4x + 1 = 3x - 5

<=> x² - 4x - 3x + 1 + 5 = 0

<=> x² - 7x + 6 = 0

<=> x² - 6x - x + 6 = 0

<=> x(x - 6) - (x - 6) = 0

<=> (x - 1)(x - 6) = 0

<=> \(\left[{}\begin{matrix}x-1=0\\x-6=0\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x=1\\x=6\end{matrix}\right.\)

\(a,\Rightarrow\left[{}\begin{matrix}x-1=2x\\1-x=2x\end{matrix}\right.\Rightarrow\left[{}\begin{matrix}x=-1\\x=\dfrac{1}{3}\end{matrix}\right.\\ b,\Rightarrow\left[{}\begin{matrix}x+x-2=2\left(x\ge2\right)\\x+2-x=2\left(0\le x< 2\right)\\-x+2-x=2\left(x< 0\right)\end{matrix}\right.\Rightarrow\left[{}\begin{matrix}x=2\left(x\ge2\right)\left(tm\right)\\x=0\left(0\le x< 2\right)\left(tm\right)\\x=0\left(x< 0\right)\left(ktm\right)\end{matrix}\right.\\ \Rightarrow\left[{}\begin{matrix}x=2\\x=0\end{matrix}\right.\)

a: Ta có: \(\left|x-1\right|=2x\)

\(\Leftrightarrow\left[{}\begin{matrix}x-1=2x\left(x\ge1\right)\\x-1=-2x\left(x< 1\right)\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x=-1\left(loại\right)\\x=\dfrac{1}{3}\left(nhận\right)\end{matrix}\right.\)

X x 9.6 + X x 40% = 2.18

X x (9.6+40%) = 2.18

X x 10 = 2.18

X = 2.18 : 10

X = 0.218

a) \(\left(2x+1\right)\left(x-2\right)-2x^2=0\)

\(\Leftrightarrow2x^2-4x+x-2-2x^2=0\)

\(\Leftrightarrow\left(2x^2-2x^2\right)-\left(4x-x\right)-2=0\)

\(\Leftrightarrow-3x-2=0\)

\(\Leftrightarrow-3x=2\)

\(\Leftrightarrow x=-\dfrac{2}{3}\)

b) \(\left(x+3\right)\left(2x-1\right)+x^2=9\)

\(\Leftrightarrow\left(x+3\right)\left(2x-1\right)+x^2-9=0\)

\(\Leftrightarrow\left(x+3\right)\left(2x-1\right)+\left(x+3\right)\left(x-3\right)=0\)

\(\Leftrightarrow\left(x+3\right)\left(2x-1+x-3\right)=0\)

\(\Leftrightarrow\left(x+3\right)\left(3x-4\right)=0\)

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

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

`#3107.101107`

a)

`(2x + 1)(x - 2) - 2x^2 = 0`

`<=> 2x^2 - 3x - 2 - 2x^2 = 0`

`<=> -3x - 2 = 0`

`<=> -3x = 2`

`<=> x = -2/3`

Vậy, `x=-2/3`

b)

`(x + 3)(2x - 1) + x^2 = 9`

`<=> 2x^2 - 5x - 3 + x^2 = 9`

`<=> 3x^2 - 5x - 3 = 9`

`<=> 3x^2 - 3x - 12 = 0`

`<=> 3x^2 + 4x - 9x - 12 = 0`

`<=> (3x^2 - 9x) + (4x - 12) = 0`

`<=> 3x(x - 3) + 4(x - 3) = 0`

`<=> (3x + 4)(x - 3) = 0`

`<=>` TH1: `3x + 4 = 0`

`<=> 3x = -4`

`<=> x = -4/3`

TH2: `x - 3 = 0`

`<=> x = 3`

Vậy,` x \in {-4/3; 3}.`

a) Ta có: \(\sqrt{x}-1=6\)

\(\Leftrightarrow\sqrt{x}=7\)

hay x=49

Vậy: x=49

b) Ta có: \(\sqrt{x}< 4\)

nên x<16

Vậy: \(0\le x< 16\)

a,

`X-14,5=4,5xx6`

`X-14,5 = 27`

`X         = 27 + 14,5`

`X        = 41,5`

   Vậy ` X = 41,5 `

b,

`X-4,32=25xx4`

`X-4,32= 100`

`X        = 100 + 4,32 `

`X        = 104,32 `

          Vậy ` X = 104,32`

A, x-14,5=4,5×6

X-14,5= 27

X= 27 + 14,5

X=41,5

B, x-4,32= 25×4

    X-4,32=100

    X= 100 + 4,32

     X=104,32

A, x-14,5=4,5×6

X-14,5= 27

X= 27 + 14,5

X=41,5

B, x-4,32= 25×4

    X-4,32=100

    X= 100 + 4,32

     X=104,32

a: =>10+3x-3=6x+10

=>3x-3=6x

=>-3x=3

=>x=-1

b: =>x+1=0 hoặc x-2=0

=>x=-1 hoặc x=2

a) \(10+3\left(x-1\right)=10+6x\)

\(\Rightarrow10+3x-3=10+6x\)

\(\Rightarrow3x-6x=10-10+3\)

\(\Rightarrow-3x=3\)

\(\Rightarrow x=-\dfrac{3}{3}\)

\(\Rightarrow x=-1\)

b) \(\left(x+1\right)\left(x-2\right)=0\)

\(\Rightarrow\left[{}\begin{matrix}x+1=0\\x-2=0\end{matrix}\right.\)

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