Tìm số nguyên x, biết:
1) -16 + 23 + x = - 16

7+x=-16

    x=-16-7

    x=-23
2) 2x – 35 = 15

2x=15+35

2x=50

  x=50:2

  x=25
3) 3x + 17 = 12

3x=12-17

3x=-5

  x=-5/3
4) (2x – 5) + 17 = 6

2x-5=6-17

2x-5=-11

2x=-11+5

2x=-6

  x=-6:2

  x=-3
5) 10 – 2(4 – 3x) = -4

2(4-3x)=10-(-4)

2(4-3x)=14

4-3x=14:2

4-3x=7

3x=4-7

3x=-3

  x=-3:3

  x=-1
6) - 12 + 3(-x + 7) = -18

3(-x+7)=-18-(-12)

3(x+7)=-6

x+7=-6:3

x+7=-2

    x=-2-7

    x=-9

tự đi mà làm

\(a,\Rightarrow x+35=103\\ \Rightarrow x=68\\ b,\Rightarrow x+7=42\\ \Rightarrow x=35\\ c,\Rightarrow x-15=9\\ \Rightarrow x=24\\ d,\Rightarrow x+23=31\\ \Rightarrow x=8\\ e,\Rightarrow18-x=6\\ \Rightarrow x=12\\ f,\Rightarrow x+14=34\\ \Rightarrow x=20\\ g,\Rightarrow2x+1=21\\ \Rightarrow x=11\\ h,\Rightarrow3\left(x+1\right)=99\\ \Rightarrow x+1=33\Rightarrow x=32\\ i,5\left(x-3\right)=25\\ \Rightarrow x-3=5\\ \Rightarrow x=8\\ j,\Rightarrow8\left(2x+7\right)=88\\ \Rightarrow2x+7=11\Rightarrow x=2\\ k,\Rightarrow5\left(x+4\right)=85\\ \Rightarrow x+4=17\\ \Rightarrow x=13\)

a.\(2x^2+5x+8+\sqrt{x}=x^2+3x+35+x^2+2x-7\)

\(=2x^2+5x+8+\sqrt{x}=2x^2+5x+28\Leftrightarrow\sqrt{x}=20\Leftrightarrow x=400.\)

b.\(3\sqrt{x}+7x+5=\sqrt{x}+4x-6+3x+18\)

\(=3\sqrt{x}+7x+5=\sqrt{x}+7x+12\Leftrightarrow2\sqrt{x}=7\Leftrightarrow x=\frac{49}{4}.\)

c.\(8\sqrt{x}+2x-9=5x+7+6\sqrt{x}-3x-12.\)

\(=8\sqrt{x}+2x-9=2x+6\sqrt{x}-5\Leftrightarrow2\sqrt{x}=4\Leftrightarrow x=4.\)

d.\(2\sqrt{3x}+11x-18=5x+3+6\sqrt{3x}+6x-21\)

\(=2\sqrt{3x}+11x-18=11x+6\sqrt{3x}-19\Leftrightarrow4\sqrt{3x}=1\)

\(\Leftrightarrow\sqrt{3x}=\frac{1}{4}\Leftrightarrow3x=\frac{1}{16}\Leftrightarrow x=\frac{1}{48}.\)

a) \(2x^2+5x+8+\sqrt{x}=x^2+3x+35+x^2+2x-7\)

<=> \(2x^2+5x+8+\sqrt{x}=2x^2+5x+28\)

<=> \(2x^2+5x+8+\sqrt{x}-\left(2x^2+5\right)=28\)

<=> \(\sqrt{x}+8=28\)

<=> \(\sqrt{x}=28-8\)

<=> \(\sqrt{x}=20\)

<=> \(\left(\sqrt{x}\right)^2=20^2\)

<=> x = 400

=> x = 400

b) \(3\sqrt{x}+7x+5=\sqrt{x}+4x-6+3x+18\)

<=> \(3\sqrt{x}+7x+5=7x+\sqrt{x}+12\)

<=> \(3\sqrt{x}+5=7x+\sqrt{x}+12-7x\)

<=> \(3\sqrt{x}+5=\sqrt{x}+12\)

<=> \(3\sqrt{x}=\sqrt{x}+12-5\)

<=> \(3\sqrt{x}=\sqrt{x}+7\)

<=> \(3\sqrt{x}-\sqrt{x}=7\)

<=> \(2\sqrt{x}=7\)

<=> \(\sqrt{x}=\frac{7}{2}\)

<=> \(\left(\sqrt{x}\right)^2=\left(\frac{7}{2}\right)^2\)

<=> \(x=\frac{49}{4}\)

=> \(x=\frac{49}{4}\)

c) \(8\sqrt{x}+2x-9=5x+7+6\sqrt{x}-3x-12\)

<=> \(8\sqrt{x}+2x-9=2x+6\sqrt{x}-5\)

<=> \(8\sqrt{x}-9=2x+6\sqrt{x}-5-2x\)

<=> \(8\sqrt{x}-9=6\sqrt{x}-5\)

<=> \(8\sqrt{x}=6\sqrt{x}-5+9\)

<=> \(8\sqrt{x}=6\sqrt{x}+4\)

<=> \(8\sqrt{x}-6\sqrt{x}=4\)

<=> \(2\sqrt{x}=4\)

<=> \(\sqrt{x}=2\)

<=> \(\left(\sqrt{x}\right)^2=2^2\)

<=> x = 4

=> x = 4

d) \(2\sqrt{3x}+11x-18=5x+3+6\sqrt{3x}+6x-21\)

<=> \(2\sqrt{3x}+11x-18=11x+6\sqrt{3x}-18\)

<=> \(2\sqrt{3x}+11x-18-\left(11x-18\right)=6\sqrt{3x}\)

<=>\(2\sqrt{3x}=6\sqrt{3x}\)

<=> \(2\sqrt{3x}-6\sqrt{3x}=0\)

<=>\(-4\sqrt{3x}=0\)

<=> \(\sqrt{3x}=0\)

<=> \(\left(\sqrt{3x}\right)^2=0^2\)

<=> 3x = 0

<=> x = 0

=> x = 0

e: =>2/7-x=2/5

=>7-x=5

=>x=2

f: =>2x+3/3=10/3

=>2x+3=10

=>2x=7

=>x=7/2

g: =>(14+x)/7=15/7

=>x+14=15

=>x=1

h: =>(2x+3)/x=13/x

=>2x+3=13

=>2x=10

=>x=5

(-2x-7)-(-5x+18)=35

=>-2x-7+5x-18=35

=>3x-25=35

=>3x=35+25

=>3x=60

=>x=60:3

=>x=20

(-2x-7)-(-5x+18)=35

-2x-7+5x-18=35

(-2x+5x)-(7+18)=35

3x-25=35

3x=35+25

3x=60

x=60:3

x=20

Vậy x=20

\(\left(-2x-7\right)-\left(5x+18\right)=35.\)

\(\Leftrightarrow-2x-7-5x-18=35\)

\(\Leftrightarrow-7x-25=35\)

\(\Rightarrow-7x=60\)

\(\Leftrightarrow x=-\frac{60}{7}\)

Vậy \(x=-\frac{60}{7}\)

1 ) ( 2x - 15 ) + 17 = 6

=> 2x - 15 = 6 - 17

=> 2x - 15 = - 11

=> 2x = - 11 + 15

=> 2x = 4

=> x = 4: 2

=> x = 2

Vậy x = 2

2) 15 - ( 4 - 3x ) = -4

=> 4 - 3x = 15 - ( -4 )

=> 4 - 3x = 19

=> 3x = 4 - 19

=> 3x = -15

=> x = -15 : 3

=> x = -5

Vậy x = -5

3) -21 + 3 . ( -x + 7 ) = - 18

=> 3 . ( -x + 7 ) = ( -18 ) - ( -21 )

=> 3 . ( -x + 7 ) = 3

=> -x +7 = 3 : 3

=> -x + 7 = 1

=> -x = 1 - 7

=> -x = - 6

=> x = - (- 6 )

Vậy x = - ( -6 )

4 ) 78 : ( 3x - 2 ) = -3

=> 3x - 2 = 78 : ( -3)

=> 3x - 2 = -26

=> 3x = -26 + 2

=> 3x = -24

=> x = -24 : 3

=> x = -8

Vậy x = -8

5) -35 : 5 . ( -3 - 2x ) = 35

=> -7 . ( -3 ) + 2x = 35

=> -3 + 2x = 35 : ( -7)

=> -3 + 2x = -5

=> 2x = (-5) - (-3)

=> 2x = -2

=> x = -2 : 2

=> x = -

Vậy x = -1

~ Chúc bạn học tốt ~

1/ (2x – 15) + 17 = 6

<=> 2x=4

<=> x=2
2/ 15 – (4 – 3x) = - 4

<=> 3x=-15

<=> x=-5
3/ - 21 + 3(-x + 7) = -18

<=> -3x=-18

<=> x=6
4/ 78 : (3x – 2) = -3

<=> 3x-2=-26

<=> 3x=-24

<=> x=-8
5/ -35 : 5.(-3 – 2x) = 35

<=> -3-2x=-7

<=> 2x=4

<=> x=2

Bài 13:

1/ (2x -15) + 17 = 6

\(\Leftrightarrow\) 2x - 15 = 6 - 17

\(\Leftrightarrow\) 2x - 15 = -11

\(\Leftrightarrow\) 2x = -11 + 15

\(\Leftrightarrow\) 2x = 4

\(\Leftrightarrow\) x = 4 : 2

\(\Leftrightarrow\) x = 2.

Vậy x = 2.

2/ 15 - (4 - 3x) = -4

\(\Leftrightarrow\) 4 - 3x = 15+4

\(\Leftrightarrow\) 4 - 3x = 19

\(\Leftrightarrow\) 3x = 4 - 19

\(\Leftrightarrow\) 3x = -15

\(\Leftrightarrow\) x = -15 : 3

\(\Leftrightarrow\) x = -5.

Vậy x = -5.

3/ -21 + 3(-x + 7 ) = -18

\(\Leftrightarrow\) 3(-x + 7 ) = -18 + 21

\(\Leftrightarrow\) 3(-x + 7 ) = 3

\(\Leftrightarrow\) -x + 7 = 3 : 3

\(\Leftrightarrow\) -x + 7 = 1

\(\Leftrightarrow\) -x = 1 - 7

\(\Leftrightarrow\) -x = -6

\(\Leftrightarrow\) x = 6.

Vậy x = 6.

4/ 78 : (3x - 2) = -3

\(\Leftrightarrow\) 3x - 2 = 78 : (-3)

\(\Leftrightarrow\) 3x - 2 = -26

\(\Leftrightarrow\) 3x = (-26) + 2

\(\Leftrightarrow\) 3x = -24

\(\Leftrightarrow\) x = (-24) : 3

\(\Leftrightarrow\) x = -8.

Vậy x = -8.

5/ -35 : 5.(-3 - 2x) = 35

\(\Leftrightarrow\) (-7).(-3-2x)= 35

\(\Leftrightarrow\) (-3)-2x=35:(-7)

\(\Leftrightarrow\) (-3)-2x=-5

\(\Leftrightarrow\) -2x=(-3)+5

\(\Leftrightarrow\) -2x=2

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

\(\Leftrightarrow\) x=-1.

Vậy x = -1.

Chúc bạn học tốt !!!!!!

a, 4x+18:2 = 13

4x+9 = 13

x = 1

b, 48 – 3(x+5) = 24

3(x+5) = 24

x + 5 = 8

x = 3

c,  2 x - 2 0 = 3 5 : 3 3

2x – 1 =  3 2

2x = 10

x = 5

d, (15+x):3 =  3 15 : 3 12

(15+x):3 =  3 3

(15+x):3 = 27

15 + x = 54

x = 39

a) 42 - x = 5

x = 42 - 5

x = 37

b) 15.(x + 4) = 75

x + 4 = 75 : 15

x + 4 = 5

x = 5 - 4

x = 1

d) x + 18 = 12

x = 12 - 18

x = -6

e) 2x - 15 = -19

2x = (-19) + 15

2x = -4

x = -4 : 2

x = -2

f) 36 : (x^3 - 12) = -3

x^3 - 12 = 36 : (-3)

x^3 - 12 = -12

x^3 = 0

=> x = 0

g)x + 15 = 35

x = 35 - 15

x = 20

h) 2x - 13 = 3^2

2x - 13 = 9

2x = 9 + 13

2x = 22

x = 22 : 2

x = 11

a) 42-x=5

         x=42-5

         x= 37

b)15*(x+4)=75

        x+4=75:15

        x+4=5

        x    =5-4

       x     = 1

a) 42 - x = 5

x = 42 - 5

x = 37

b) 15.(x + 4) = 75

x + 4 = 75 : 15

x + 4 = 5

x = 5 - 4

x = 1

d) x + 18 = 12

x = 12 - 18

x = -6

e) 2x - 15 = -19

2x = (-19) + 15

2x = -4

x = -4 : 2

x = -2

f) 36 : (x^3 - 12) = -3

x^3 - 12 = 36 : (-3)

x^3 - 12 = -12

x^3 = 0

=> x = 0

g)x + 15 = 35

x = 35 - 15

x = 20

h) 2x - 13 = 3^2

2x - 13 = 9

2x = 9 + 13

2x = 22

x = 22 : 2

x = 11