1. 3x - 17 = x+3

    3x - x = 3 + 17

    2x      = 20

      x      = 20 :2

      x      = 10

2.  |x-3| - 12 = |-5|

     |x-3| -12  = 5

     |x-3|       =  5 + 12

     |x-3|       = 17

=> x-3 = +17 , -17

             x      = 17 + 3

             x      = 20

            x       =  -17 + 3

            x       = -14

3 . 25 - ( x -5 )  = -415 -( 15 -415)

     25 - x +5     =  -415 - 15 +415

     25 - x +5      =  ( -415 + 415) -15 

     25 - x +5     =    0-5 = -5

     25 - x          =    -5-5

     25 - x          = -10

           x           =  25 - -10

           x           =  35

4.  ( x -3 ) . ( 2x +6 ) = 0

=> x-3 = 0 hoặc 2x +6 = 0

           x      = 0 + 3 = 3

          2x      =  0-6=-6

           x       =  -6 : 2

           x       = -3

\(1;3x-17=x+3\)

\(\Leftrightarrow3x-x=3+17\)

\(\Leftrightarrow2x=20\)

\(\Rightarrow x=10\)

\(2;\left|x-3\right|-12=\left|-5\right|\)

\(\Leftrightarrow\left|x-3\right|-12=5\)

\(\Leftrightarrow\left|x-3\right|=5+12\)

\(\Leftrightarrow\left|x-3\right|=17\)

\(\Rightarrow\orbr{\begin{cases}x-3=17\\3-x=17\end{cases}\Leftrightarrow}\orbr{\begin{cases}x=17+3\\-x=17-3\end{cases}\Leftrightarrow\orbr{\begin{cases}x=20\\x=-14\end{cases}}}\)

\(3;25-\left(x-5\right)=-415-\left(15-415\right)\)

\(\Leftrightarrow25-x+5=-415-15+415\)

\(\Leftrightarrow-x=-415-15+415-25-5\)

\(\Leftrightarrow-x=-45\)

\(\Rightarrow x=45\)

\(4;\left(x-3\right)\left(2x+6\right)=0\)

\(\Rightarrow\orbr{\begin{cases}x-3=0\\2x+6=0\end{cases}\Leftrightarrow\orbr{\begin{cases}x=3\\x=-3\end{cases}}}\)

3x-17=x+3

3x-x=3+17

2x=20

x=10

lx-3l - 12 = l-5l = 5

lx-3l = 5+12=17

<=>\(\orbr{\begin{cases}x-3=17\\x-3=-17\end{cases}\Leftrightarrow\orbr{\begin{cases}x=20\\x=-14\end{cases}}}\)

A , 3 - ( 17 - x ) = 289 -  ( 36 + 289 )

3 - 17 + x = 0 - 36

-14 + x = -36

x = -36 - ( - 14 ) = -22

B, 25 - ( x + 5 ) = -415 - ( 15 - 415 )

25 - x - 5 = 0 - 15

20 - x = -15

x = 20 - ( - 15 ) = 35

C , 34 + ( 21 - x ) = ( 3747 - 30 ) - 3746

34 + 21 - x = 1 - 30 

55 - x = -29

x = 55 - (-29 ) = 74

D , -2x -  ( x -17 ) = 34 - ( -x + 25 )

- 2x - x + 17 = 34 - 25 + x

- 3x + 17 = 9 + x

- 3x - x = 9 - 17

-4x = -8

x = -8 : ( - 4 )

x = 2

E , 17x + ( -16x - 37 ) = x + 43

17x - 16x -37 = x + 43

x - 37 = x + 43

-37 - 43 = x - x 

- 80 = 0      ( vô lý )

G , ( x + 12 ) . (x - 3 ) = 0

\(\hept{\begin{cases}x+12=0\\x-3=0\end{cases}}\)

\(\hept{\begin{cases}x=-12\\x=3\end{cases}}\)

a, 3- (17-x) = 289 - (36+289)

3 - (17 - x )= 289 - 325

3 - (17 - x )= -36

17 - x =3 - (-36)

17 - x =39

       x = 17 - 39

       x = -22

b, 25- (x+5) = - 415 - (15 - 415)

25 - ( x + 5)= -415 - (-400)

25-( x + 5 ) =-15

x + 5 = 25 - (-15)

x+5 =40

x = 40 -5

x=35

hok tốt !

a. 3x-17=x+3=>3x-17-x+3=0=>2x-14=0=>2x=14=>x=7

mấy bài sau giải dễ lắm, áp dụng nhân từng thừa số nếu bạn chưa học lập phương trình, bạn cứ làm toán nhân như vậy nhé! chúc bạn học giỏi!!!

a) 3x - 17 = x + 3

<=> 3x - x = 17 + 3

<=> 2x = 20

<=> x = 10

Vậy x = 10

b) (x-3) - 12 = (-5)

<=> x - 3 = 7

<=> x = 10

Vậy x = 10

c)25 - (x - 5) = -415 - (15-415)

<=> 25 - (x - 5) = -15

<=> x - 5 = 40

<=> x = 45

Vậy x = 45

d) 2x - 15 = -47

<=> 2x = -32

<=> x = -16

Vậy x = -16

e) (-5)²  - (5x - 3) = 43

<=> 5x - 3 = -18

<=> 5x = -15

<=> x = -3

Vậy x = -3

g)(x - 3) (2x + 6) = 0

\(\orbr{\begin{cases}x-3=0\\2x+6=0\end{cases}}\)

\(\orbr{\begin{cases}x=3\\x=-3\end{cases}}\)

Vậy x \(\in\){ 3; -3 }

Học tốt nhá :))

a, 3x-17=x+3

3x-x=3+17

2x=20

x=20:2

x=10

a) 3x-17=x+3

3x-x=17+3

2x=20     =>x=10

b)  |x-3|-12=|-5|

|x-3|=17

x-3=17 hoặc x-3=-17

nếu x-3=17 thì x=20

nếu x-3=-17 thì x=-14

c) 2,5-(x-5)=-415-(15-415)

2,5-(x-5)=-15

x-5=2,5+15

x-5=17,5  =>x=22,5

a,3x-17=x+3

3x-x=3+17

2x=20

x=20:2

x=10

b,/x-3/-12=/-5/

/x-3/-12=5

/x-3/=17

suy ra ; x-3=-17 or x-3=17

x=-17+3                 x =17+3

x=-14                        x=20

    c,2,5-(x-5)=-415-(15-415)

2,5-(x-5)=-15

x-5=2,5-(-15)

x-5=17,5

x=17,5+5

x=22,5                     

x=-14

a, \(\Leftrightarrow\)\(2x=-32\)

\(\Leftrightarrow\)\(x=-16\)

b,\(\Leftrightarrow\)\(25-\left(5x-3\right)=64\)

\(\Leftrightarrow\)\(5x-3=-39\)

\(\Leftrightarrow\)\(5x=-36\)

\(\Leftrightarrow\)\(x=-7,2\)

c,\(\Leftrightarrow\)\(25-\left(x-5\right)=15\)

\(\Leftrightarrow\)\(x-5=10\)

\(\Leftrightarrow\)\(x=15\)

mình cần gấp

a, 28 + 2x = 35 - ( -13 )

=> 2x = 35 + 13 - 28

=>2x = 20

=> x = 10. vậy x = 10

a, \(28+2x=35+13\Leftrightarrow28+2x=48\Leftrightarrow2x=20\Leftrightarrow x=10\)

b, \(-25-x-5=415+5x-415\Leftrightarrow-6x=30\Leftrightarrow x=-5\)

Mấy bài này căng vậy?

a)4(18 - 5x) - 12(3x - 7) = 15(2x - 16) - 6(x + 14)

<=>72 - 20x - 36x +84 = 30x - 240 - 6x 84

<=> -80x = -480

<=> x = 6

b) 5(3x+5)-4(2x-3) =5x+3(2x+12)+1

<=> 15x + 25  - 8x + 12 = 5x + 6x + 36 + 1

<=> 15x + 25 - 8x + 12 - 5x - 6x - 36 - 1 = 0

<=> -4x = 0

<=> x = 0

c) 2(5x-8)-3(4x-5)=4(3x-4)+11

= 10x - 16 - 12x + 15 = 12x - 16 + 11

= -14x = -4

= x =\(\frac{2}{7}\)

d) 5x-3{4x-2[4x-3(5x-2)]}=182

= 5x - 3 . [4x - 2(4x - 15x + 6)]

= 5x - 3 . (4x - 8x + 30x - 12)

= 5x - 12x + 24x - 90x + 36

= -73x + 36 = 182

=> -73x = 182 - 36 = 146

=> x = 146 : (-73) = -2

~Hok tốt~

a)4(18 - 5x) - 12(3x - 7) = 15(2x - 16) - 6(x + 14)

<=>72 - 20x - 36x +84 = 30x - 240 - 6x 84

<=> -80x = -480

<=> x = 6

b) 5(3x+5)-4(2x-3) =5x+3(2x+12)+1

<=> 15x + 25  - 8x + 12 = 5x + 6x + 36 + 1

<=> 15x + 25 - 8x + 12 - 5x - 6x - 36 - 1 = 0

<=> -4x = 0

<=> x = 0

c) 2(5x-8)-3(4x-5)=4(3x-4)+11

= 10x - 16 - 12x + 15 = 12x - 16 + 11

= -14x = -4

= x = 2/7

d) 5x-3{4x-2[4x-3(5x-2)]}=182

= 5x - 3 . [4x - 2(4x - 15x + 6)]

= 5x - 3 . (4x - 8x + 30x - 12)

= 5x - 12x + 24x - 90x + 36

= -73x + 36 = 182

=> -73x = 182 - 36 = 146

=> x = 146 : (-73) = -2