a: =>3(x+4)=115

=>x+4=115/3

hay x=103/3

b: =>\(8^3\cdot\left(12x-64\right)=4\cdot8^4\)

\(\Leftrightarrow12x-64=32\)

=>12x=96

hay x=8

c: \(\Leftrightarrow\left(4x+28\right)\cdot23+55=175\)

=>(4x+28)x23=120

=>4x+28=120/23

=>4x=-524/23

hay x=-131/23

giúp mk với

Đề khó hiểu quá bn ơi

a)   x + 118 = 218

x = 218 – 118

x = 100

b)   18 – x = -17

X = 18 – (-17)

X = 35

c)    (-18) – x = -17

X = (-18) – (-17)

X = -1

d)124 + (118 – x) = 217

118 – x = 93

X = 118 – 93

X = 25

e) (3x – 6).3 = 3⁴

(3x – 6).3 = 81

3x – 6 = 27

3x = 33

ð X = 11

g) 23.(42 – x) = 46

42 – x = 2

ð X = 40

h) 84 – (3x + 8) = 34

3x + 8 = 84 – 34

3x + 8 = 50

3x = 50 – 8

3x = 42

X = 42 : 3

ð X = 14

i)               3.(2x + 1) – 19 = 14

3.(2x + 1) = 14 + 19

3.(2x + 1) = 33

2x + 1 = 33 : 3

2x + 1 = 11

2x = 11 – 1

2x = 10

X = 10 : 2

ð X = 5

k) 6x – 302 = 2³.5

6x – 302 = 40

6x = 40 + 302

6x = 342

X = 342 : 6

ð X = 57

m) (x – 1)² = 81

(x – 1)² = 9²

ð X – 1 = 9

ð X = 9 + 1

ð X = 10

n) 2^x+1 – 5 = 27

2^x+1 = 27 + 5

2^x+1 = 32

2^x+1 = 2⁵

ð X = 4

a) \(x+118=218\)

    \(x=218-118\)

    \(x=100\) 

b)\(18-x=-17\)

   \(-x=-18-17\)

    \(-x=-35\)

     \(x=35\)

c)\(\left(-18\right)-x=-17\)

     \(-x=18-17\)

     \(-x=1\)

      \(x=-1\)

d)\(124+\left(118-x\right)=217\)

    \(118-x=217-124\)

     \(118-x=93\)

     \(x=25\)

e) \(\left(3x-6\right).3=3^4\)

     \(3x-6=3^3\)

     \(3x-6=27\)

     \(x=11\)

g)\(23.\left(42-x\right)=46\)

    \(42-x=2\)

     \(x=40\)

h) \(84-\left(3x+8\right)=34\)

    \(3x+8=50\)

     \(x=14\)

 i)  \(3\left(2x+1\right)-19=14\)

      \(3\left(2x+1\right)=33\)

       \(2x+1=11\)  

        \(x=5\)

k) \(6x-302=2^3.5\)

    \(6x-302=8.5\)

    \(x=57\)

m) \(\left(x-1\right)^2=81\)

      \(\left(x-1\right)^2=9^2\)

       \(x-1=9\)

       \(x=10\)

n) \(2^{x+1}-5=27\)

    \(2^{x+1}=32\)

    \(2^{x+1}=2^5\)

   \(x+1=5\)  

     \(x=4\)

m) \(2^x+2^{x+1}+2^{x+2}=56\)

    \(2^x.1+2^x.2+2^x.2^2=56\)

    \(2^x\left(1+2+4\right)=56\)

     \(2^x=8\)

    \(2^x=2^3\)

     \(x=3\)

   \(2^x=8\)

a, 128 – 3(x+4) = 23

b,  12 x - 4 3 . 8 3 = 4 . 8 4

c, [(4x+28).3+55]:5 = 35

d, 720:[41 – (2x – 5)] =  2 3 . 5

a) \(-2011-\left(200-2011\right)\)

\(=-2011-200+2011\)

\(=\left(-2011+2011\right)-200\)

\(=0-200\)

\(=-200\)

b) \(\left(-2\right)^2-\left(-2000\right)^0+\left(-1\right)^{2018}-\left|-20\right|\)

\(=4-1+1-20\)

\(=4-20\)

\(=-16\)

Bài 1 :

\(a)-2011-(200-2011)\)

\(=-2011-(200+2011)\)

\(=(-2011+2011)-200\)

\(=0-200=-200\)

\(b)(-2)^2-(-2000)^0+(-1)^{2018}-\left|-20\right|\)

\(=4-1+1-20\)

\(=4-20=-16\)

\(c)23\cdot18-23\cdot26+(-23)\cdot2\)

\(=23\cdot(18-26)+-(23\cdot2)\)

\(=23\cdot(-8)+(-46)\)

\(=-230\)

Bài 2 : Tìm số nguyên x biết :

\(a)3x-(-5)=20\)

\(\Rightarrow3x+5=20\)

\(\Rightarrow3x=20-5\)

\(\Rightarrow3x=15\Rightarrow x=5\)

\(b)3(x+2)=-4+(-2)^3\)

\(\Rightarrow3(x+2)=-4+(-8)\)

\(\Rightarrow3(x+2)=-12\)

\(\Rightarrow x+2=-12\div3\)

\(\Rightarrow x+2=-4\)

Tự tìm x câu b, và câu c,

Bài 3 tự làm

c) \(23.18-23.26+\left(-23\right).2\)

\(=23\cdot\left(18-26-2\right)\)

\(=23.\left(-10\right)\)

\(=-230\)

a) \(3x-\left(-5\right)=20\)

\(\Leftrightarrow3x=20-5\)

\(\Leftrightarrow3x=15\)

\(\Leftrightarrow x=15\div3\)

\(\Leftrightarrow x=5\)

Vậy x = 5

a: \(=\dfrac{5\left(x+2\right)}{10xy^2}\cdot\dfrac{12x}{x+2}=\dfrac{60x}{10xy^2}=\dfrac{6}{y^2}\)

b: \(=\dfrac{x-4}{3x-1}\cdot\dfrac{3\left(3x-1\right)}{\left(x-4\right)\left(x+4\right)}=\dfrac{3}{x+4}\)

c: \(=\dfrac{2\left(2x+1\right)}{\left(x+4\right)^2}\cdot\dfrac{\left(x+4\right)}{3\left(x+3\right)}=\dfrac{2\left(2x+1\right)}{3\left(x+3\right)\left(x+4\right)}\)

d: \(=\dfrac{5\left(x-1\right)}{3\left(x+1\right)}\cdot\dfrac{x+1}{x-1}=\dfrac{5}{3}\)