2:

a: =>2(x+1)=26

=>x+1=13

=>x=12

b: =>(6x)^3=125

=>6x=5

=>x=5/6(loại)

c: =>\(7\cdot3^x\cdot\dfrac{1}{3}+11\cdot3^x\cdot3=318\)

=>3^x=9

=>x=2

d: -2x+13 chia hết cho x+1

=>-2x-2+15 chia hết cho x+1

=>15 chia hết cho x+1

=>x+1 thuộc {1;3;5;15}

=>x thuộc {0;2;4;14}

e: 4x+11 chia hết cho 3x+2

=>12x+33 chia hết cho 3x+2

=>12x+8+25 chia hết cho 3x+2

=>25 chia hết cho 3x+2

=>3x+2 thuộc {1;-1;5;-5;25;-25}

mà x là số tự nhiên

nên x=1

1: 

a: Đặt A=2^2024-2^2023-...-2^2-2-1

Đặt B=2^2023+2^2022+...+2^2+2+1

=>2B=2^2024+2^2023+...+2^3+2^2+2

=>B=2^2024-1

=>A=2^2024-2^2024+1=1

c: \(=\dfrac{3^{12}\cdot2^{11}+2^{10}\cdot3^{12}\cdot5}{2^2\cdot3\cdot3^{11}\cdot2^{11}}=\dfrac{2^{10}\cdot3^{12}\left(2+5\right)}{2^{13}\cdot3^{12}}\)

\(=\dfrac{7}{2^3}=\dfrac{7}{8}\)

a ) 10 x X - 1 - 3 - 5 - 7 - ... - 19 = 2 + 4 + 6 + ... + 20

10 x X - 1 - 3 - 5 - 7 - ... - 19 = 110

10 x X - ( 1 + 3 + 5 + 7 + ... + 19 ) = 110

10 x X - 100 = 110

10 x X = 110 + 100

10 x X = 210

       X = 210 : 10

       X = 21

a 10 x X-1-3-5-7-....-19 = 2+4+6+....+20

​10xX-1-3-5-7-....-19=110

​10xX=110+1+3+5+7+....+19

​10xX=210

​X=210:10

​X=21

b là 4

​

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a) 3x - 10 = 2x + 13

<=> 3x - 2x = 13+10

<=> x = 23

      Vậy x = 23

b) x + 12 = -5 - x

<=> x + x = -5 - 12

<=> 2x = -17

<=> x = -17 : 2

<=> x = -8,5

      Vậy x = -8,5

c) x + 5 = 10 - x

<=> x + x = 10 - 5

<=> 2x = 5

<=> x = 5 : 2

<=> x = 2,5

      Vậy x = 2,5

d) 6x + 2 ^ 3 = 2x - 12

<=> 6x + 8 = 2x - 12

<=> 6x - 2x = -12 - 8

<=> 4x = -20

<=> x = -20 : 4

<=> x = -5

     Vậy x = -5

e) 12 - x = x + 1

<=> -x - x = 1 - 12

<=> -2x = -11

<=> x = -11 : (-2)

<=> x = 5,5

     Vậy x= 5,5

f) 14 - 4x = 3x + 20

<=> -4x - 3x = 20 - 14

<=> -7x = 6

<=> x = 6 : (-7)

<=> x = \(-\frac{6}{7}\)

a. -13 - (5-x) = -10
-13 - 5 + x = -10
x = -10 + 13 + 5
x = 8
Vậy x = 8
b, -3x - 15 = 2x - 20
-3x - 2x = -20 + 15
-5x = -5
x = -5 : (-5)
x = 1
Vậy x = 1
c, 5 - (x-3)^2 = 20
(x-3)^2 = 5 - 20 
(x-3)^2 = -15 ( vô lí )

Vậy không có giá trị x thỏa mãn
d. | x - 12 | - (-5) = 12
| x - 12 | = 12 + (-5)
| x - 12 | = 7
x - 12  = + - 7
(+) x - 12 = 7           (+) x - 12 = -7
x = 7 + 12                        x     = -7 + 12
X = 19                              x     = 5

Vậy x thuộc { 19 ; 5 }
 

a: \(\left(5x-10\right):\left(100x^2+18\right)=0\)

=>5x-10=0

=>5x=10

=>x=2

b: (-300):20+5(3x-1)=25

=>-15+5(3x-1)=25

=>5(3x-1)=25+15=40

=>3x-1=8

=>3x=9

=>x=3

c: \(\left(2021x+12\right)^2\left(x+4\right)>0\)

mà \(\left(2021x+12\right)^2>0\forall x\) nguyên

nên x+4>0

=>x>-4

mà x nguyên

nên x∈{-3;-2;-1;...}

1. Ta có: \(\left|12-3x\right|-20=10\)

\(\Rightarrow\left|12-3x\right|=30\)

\(\Rightarrow12-3x=\pm30\)

Nếu \(12-3x=30\Rightarrow3x=-18\Rightarrow x=-6\)

Nếu \(12-3x=-30\Rightarrow3x=42\Rightarrow x=14\)

2. Ta có: \(\left(x+1\right)\left(y-2\right)=13=1.13=13.1=\left(-13\right).\left(-1\right)=\left(-1\right)\left(-13\right)\)

a) x+3=12

x=12-3

x=9

b)(x-3):2=5¹⁴:5¹²

=>(x-3):2=5²

=>(x-3):2=25

=>x-3=25.2

=>x-3=50

=>x=50+3

=>x=53

c)4x+3x=30-20:10

=>x(4+3)=30-2

=>7x=28

=>x=28:7

=>x=4

d)2x-138=2³.3²

=>2x-138=8.9

=>2x-138=72

=>2x=72+138

=>2x=210

=>x=210:2

=>x=105

a) x + 3 = 12

x = 12 - 3

x = 9

b) ( x - 3 ) : 2 = 5¹⁴ : 5¹²

( x - 3 ) : 2 = 5^14-12

( x - 3 ) : 2 = 5²

( x - 3 ) : 2 = 25

x - 3 = 50

x = 53

c) 4x + 3x = 30 - 20 : 10

7x = 28

x = 4

d) 2x - 138 = 2³ x 3²

2x - 138 = 8 x 9

2x - 138 = 72

2x = 210

x = 105

Bài 1:

a. $(-20)+x=-30$

$x-20=-30$

$x=-30+20=-(30-20)=-10$

b.

$(-10)-x=-20$

$x=(-10)-(-20)=-10+20=20-10=10$

c. Đề sai. Bạn xem lại.

d.

$x+(-3)=-7$

$x=-7-(-3)=-7+3=-(7-3)=-4$

e.

$x-(-5)=-9$

$x=(-9)+(-5)=-14$

f.

$x(-11)=12$

$x=\frac{12}{-11}=\frac{-12}{11}$

h.

$2x-10=20$

$2x=20+10=30$

$x=30:2=15$

l.

$4x-8=-8$
$4x=-8+8=0$

$x=0:4=0$

k.

$-12-(-2)x=-8$

$(-2)x=-12-(-8)=-12+8=-(12-8)=-4$

$x=(-4):(-2)=2$

Bài 2:

a. $-20-(10-x)=-3$

$10-x=-20-(-3)=-20+3=-(20-3)=-17$

$x=10-(-17)=10+17=27$

b.

$14+(14-x)=-2$
$14-x=-2-14=-16$

$x=14-(-16)=14+16=30$

c.

$-15-(x-3)=-7$

$x-3=-15-(-7)=-15+7=-8$

x=-8+3=-5$

d.

$(x+4)+(-20)=-8$

$x+4=-8-(-20)=-8+20=12$
$x=12-4=8$

e.

$-2x-2=-4$

$-2x=-4+2=-2$

$x=(-2):(-2)=1$

f.

$-2x+4=-4$

$-2x=-4-4=-8$

$x=(-8):(-2)=4$

l.

$-12-(-2)x=-2-4=-6$

$(-2)x=-12-(-6)=-12+6=-6$

$x=(-6):(-2)=3$

a) \(3x-10=2x+13\Leftrightarrow x=13+10=23\)

b) \(x+12=-5-x\Leftrightarrow2x=-17\Leftrightarrow x=-\frac{17}{2}\)

c) \(x+5=10-x\Leftrightarrow2x=5\Leftrightarrow x=\frac{5}{2}\)

d) \(6x+23=2x-12\Leftrightarrow4x=-35\Leftrightarrow x=-\frac{35}{4}\)

e) \(12-x=x+1\Leftrightarrow2x=11\Leftrightarrow x=\frac{11}{2}\)

f) \(14+4x=3x+20\Leftrightarrow x=20-14=6\)

g) \(2\left(x-1\right)+3\left(x-2\right)=x-4\Leftrightarrow2x-2+3x-6=x-4\)

\(\Leftrightarrow5x-8=x-4\Leftrightarrow4x=4\Leftrightarrow x=1\)

h ) \(3\left(4-x\right)-2\left(x-1\right)=x+20\Leftrightarrow12-3x-2x+2=x+20\)

\(\Leftrightarrow14-5x=x+20\Leftrightarrow6x=-6\Leftrightarrow x=-1\)

i ) \(4\left(2x+7\right)-3\left(3x-2\right)=24\Leftrightarrow8x+28-9x+6=24\)

\(\Leftrightarrow34-x=24\Leftrightarrow x=34-24=10\)

k) \(3\left(x-2\right)+2x=10\Leftrightarrow3x-6+2x=5x-6=10\)

\(\Leftrightarrow5x=10+6=16\Leftrightarrow x=\frac{16}{5}\)

Tự KL cho các phần

5x-16=40+x

=> 5x-16-x = 40

=> 5x-x -16=40

4x-16=40

4x= 40+16

4x=56

x= 56:4

x=14

Vậy...

4x-10=15-x

=> 4x-10+x= 15

4x+x -10=15

5x= 15+10

5x= 25

x= 25:5

x=5

Vậy....