14 : ( x - 17 ) = 2

(x-17) = 14 :2

x-17 = 7

x = 7+17

x = 24

14 : ( x - 17 ) = 2

         x - 17   = 14 : 2

         x - 17    = 7

          x          = 7 + 17

           x         = 24

Ta có : \(14:\left(x-17\right)=2\)

\(\Rightarrow x-7=14:2\)

\(\Rightarrow x-7=7\)

\(\Rightarrow x=14\)

<=>55 - 3x = 25

<=>-3x = 25 - 55
<=>-3x = -30
<=>x=10

55 - 3x = (-5)²

55 - 3x = 25

3x = 55 - 25

3x = 30

x = 30 : 3

x = 10

Vậy x = 10

55 - 3x = (-5)²

55 - 3x = 25

3x = 55 - 25

3x = 30

x = 30 : 3

x = 10

2⁵ x 3 - 3( x + 1 ) = 42

⇒ 96 - 3( x + 1 ) = 42

⇒ 3( x + 1 ) = 54

⇒ x + 1 = 18

⇔ x = 17.

Vậy x = 17.

\(2^5\times3-3\times\left(x+1\right)=42\)

\(32\times3-3\times\left(x+1\right)=42\)

\(96-3\times\left(x+1\right)=42\)

\(3\times\left(x+1\right)=54\)

\(x+1=18\)

\(x=17\)

Ta có: \(\left(2x+3\right)\left(x-4\right)+\left(x+5\right)\left(x-2\right)=\left(3x-5\right)\left(x-4\right)\)

\(\Leftrightarrow2x^2-8x+3x-12+x^2-2x+5x-10=3x^2-12x-5x+20\)

\(\Leftrightarrow-2x-22+17x-20=0\)

\(\Leftrightarrow15x=42\)

hay \(x=\dfrac{14}{5}\)

`-2/5 : x=1/2`

`=> x= -2/5 : 1/2`

`=> x= -2/5 xx 2`

`=>x= -4/5`

__

`7/6 : x = 7/4`

`=>x= 7/6 : 7/4`

`=>x=7/6 xx 4/7`

`=>x= 28/42`

`=>x=2/3`

tìm x hả

\(x=\dfrac{-2}{5}:\dfrac{1}{2}\)

\(x=\dfrac{-4}{5}\)

b. \(x=\dfrac{7}{6}:\dfrac{7}{4}\)

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

Diện tích là: 128 m²

\(128m^2\)

a. -20+5=-15 

b. 7

c. 35 + (-4)= 31 

d. -129-37+29-63= -100-100 = -200 

e. 217 -315-117+215 =100-100=0 

f. 15:(-3)+24:2 = -5 + 12 = 7 

g. (-5).(-7)-3.(14)= 35 - 42 = -7 

H. (-15)x(-129+29) = -15 x -100 =1500 

i. 13 x (-125+25) =13 x -100 = -1300 

k. 37(-135+35) = 37 x -100 = -3700

Ta có: 5 = 2 + 3

           9 = 4 + 5

           13 = 6 + 7

           17 = 8 + 9

Do: x = a + (a + 1) (a thuộc N)

Nên: 1 + 5 + 9 + 13 + 16 + ... + x = 1 + 2 + 3 + 4 + 5 + 6 + 7 + ... + a + (a + 1) = 501501

Hay (a + 1)(a + 2) = 10031002 = 1001 . 1002 => a = 1000

=> x = 1000 + (1000 + 1) + 2001

=> x = 2001

1) 13-(x-7)=5

<=> 13 - x + 7 = 5

<=> x = 15

2) /x/=2015 => x = 2015 hoặc x = -2015

3) 2x+17=15+x

<=> x = -2

4) 2x-9=-17

<=> 2x = -8

<=> x = -4

1) 13-(x-7)=5

<=>13-x+7=5

<=>20-x=5

<=>x=15

Vậy x=15

2) /x/=2015

<=> x= 2015 hoặc x=-2015

Vậy \(x\in\left\{\pm2015\right\}\)

3) 2x+17=15+x

<=>2x+17-15-x=0

<=>x+2=0

<=>x=-2

Vậy x=-2

4) 2x-9=-17

<=> 2x=-8

<=>x=-4

Vậy x=-4

tìm x biết 

a) 13 - (x - 7) = 5

x - 7 = 13 - 5

x - 7 = 8

x = 8 + 7 

x = 15

    vậy x = 15

b) |x| = 2015

=> x = 2015; -2015

    vậy x = 2015; -2015

d) 2x - 9 = -17

2x = -17 + 9

2x = -8

x = -8 : 2

x = -4

    vậy x = -4