a) |-18| . 941 + 59 . 18

= 18 . 941 + 59 . 18

= ( 941 + 59 ) . 18

= 1000 . 18

= 18000

b) 81 : 3³  + 16 : 2³

= 81 : 27 + 16 : 8

= 3 + 2

= 5

c) 30 - [ 40 - ( 6 - 1)²]

= 30 - [ 40 - 5² ]

= 30 - [ 40 - 25 ]

= 30 - 15

= 15

d) 17 . 85 + 15 . 17 - 150

= ( 85 + 15 ) . 17 -  150 

= 100 . 17 - 150 

= 1700 - 150

= 1550

a, \(\left|-18\right|\cdot941+59\cdot18=18\cdot941+59\cdot18=18\cdot\left(941+59\right)=18\cdot1000=18000\)

b, \(81:3^3+16:2^3=81\cdot27+16\cdot8=2187+128=2315\)

c, \(30-\left[40-\left(6-1\right)^2\right]=30-\left[40-5^2\right]=30-\left[40-25\right]=30-15=15\)

d, \(17\cdot85+15\cdot17-150=17\cdot\left(85+15\right)-150=17\cdot100-150=1700-150=1550\)

dễ mà

a) |-18| . 941 + 59 . 18

= 18 . 941 + 59 . 18

= 18 . (941 + 59)

= 18 . 1000

= 18000

b) 81 : 3³ - 16 : 2³

= 81 : 27 - 16 : 8

= 3 - 2

= 1

c) 30 - [40 - (6 - 1)²]

= 30 - (40 - 5²)

= 30 - (40 - 25)

= 30 - 15

= 15

d) |-17| + |-35| + 40

= 17 + 35 + 40

= 52 + 40

= 92

a)  3x – 15 = 25 – 5x 

=> 3x + 5x = 25 + 15

=> 8x = 40

=> x = 5

 b) 3x - 17 = 2x – 7     

=> 3x - 2x = -7 + 17

=> x = 10

 c) 2x – 17 =  – (3x – 18)

=> 2x - 17 = -3x + 18

=> 2x + 3x = 18 + 17

=> 5x = 35

=> x = 7

d) 3x – 14 = 2(x – 9) + 1

=> 3x - 14 = 2x - 18 + 1

=> 3x - 2x = -18 + 1 + 14

=> x = -3

f) (x – 5)² = 9          

\(\Rightarrow\left[{}\begin{matrix}x-5=3\\x-5=-3\end{matrix}\right.\)

\(\Rightarrow\left[{}\begin{matrix}x=8\\x=2\end{matrix}\right.\)

a) Ta có: \(3x-15=25-5x\)

\(\Leftrightarrow3x-15-25+5x=0\)

\(\Leftrightarrow8x-40=0\)

\(\Leftrightarrow8x=40\)

hay x=5

Vậy: x=5

b) Ta có: \(3x-17=2x-7\)

\(\Leftrightarrow3x-17-2x+7=0\)

\(\Leftrightarrow x-10=0\)

hay x=10

Vậy: x=10

c) Ta có: \(2x-17=-\left(3x-18\right)\)

\(\Leftrightarrow2x-17=-3x+18\)

\(\Leftrightarrow2x-17+3x-18=0\)

\(\Leftrightarrow5x-35=0\)

\(\Leftrightarrow5x=35\)

hay x=7

Vậy: x=7

d) Ta có: \(3x-14=2\left(x-9\right)+1\)

\(\Leftrightarrow3x-14=2x-18+1\)

\(\Leftrightarrow3x-14-2x+18-1=0\)

\(\Leftrightarrow x+3=0\)

\(\Leftrightarrow x=-3\)

Vậy: x=-3

f) Ta có: \(\left(x-5\right)^2=9\)

\(\Leftrightarrow\left[{}\begin{matrix}x-5=3\\x-5=-3\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x=8\\x=2\end{matrix}\right.\)

Vậy: \(x\in\left\{2;8\right\}\)

Bài 2. Tìm x, biết :                                

a) \(3x-15=25-5x\)

\(\Leftrightarrow8x=40\)

\(\Leftrightarrow x=5\)

Vậy x = 5

b) \(3x-17=2x-7\)

\(\Leftrightarrow x=10\)

Vậy x = 10

c) \(2x-17=-\left(3x-18\right)\)

\(\Leftrightarrow2x-17=18-3x\)

\(\Leftrightarrow5x=35\)

\(\Leftrightarrow x=7\)

Vậy x = 7

d) \(3x-14=2\left(x-9\right)+1\)

\(\Leftrightarrow3x-14=2x-18+1\)

\(\Leftrightarrow3x-14=2x-17\)

\(\Leftrightarrow x=-3\)

Vậy x = -3

e) \(\left(x-5\right)^2=9\)

\(\Rightarrow\left[{}\begin{matrix}x-5=3\\x-5=-3\end{matrix}\right.\)

\(\Leftrightarrow\left[{}\begin{matrix}x=8\\x=2\end{matrix}\right.\)

Vậy x = {8; 2}

thu gọn 7^3*7^5

Oh no nhiều kí tự đặc biệt quá

dễ quá mình ko làm  đc 

Bài 1: 

a: =25+75=100

b: =60-17-43+12=12

c: =-2-18=-20

d: =-3+36-17=36-20=16

Bài 2: 

a: =-102

b: =-1000

c: =12x15=180

d: =21x(-10)=-210

B1

a 100

b 12

c -20

d 16

B2

a -102

b -1000

c 180

d -210

Bài 1:Tính

 a)(-12)+25+75+12 = 100

b)60+12+(-17)+(-43)=12
c)(-2)+(-87)+(-18)+87=-20
d)(-1)+(-2)+36+(-17)=16
Bài 2:Tính
b)8 . (-125)=-100
c)(-12) . (-15)=180
d)21 . (- 3)+(- 21 ) . 7=-210

a)x-2=6-5x-16

   6x= -8

    x= -4/3

b)-5x-(-3)-x=13-x

-5x+3-x=13-x

-5x=10

x=-2

c)15-(x-7)=-21-x

15-x+7=-21-x

22=-21 ( vô lí)

x không có giá trị

D)3x+17=2+3x+15

17=17

x có vô số giá trị

e) x-45-(x-9)=-35-x

x-45-x+9=-35-x

-x=1

x=-1

f) -5+x=15-x-2x

4x=20

x=5

g) 2x-(-17) =15

2x+17=15

2x=-2

x=-1

a) 2436:x=12

           x=2436:12

          x=203

b) 6x-5=613

       6x=613+5

       6x=618

        x=618:6

        x=103

c) 12(x-1)=0

       x-1=0:12

       x-1=0

         x=0+1

         x=1

d) 0:x=0

 =>x\(\in\)N*

tick đúng nha

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

Bài 1: 

Ta có: \(x-35\%\cdot x=\dfrac{1}{25}\)

\(\Leftrightarrow65\%\cdot x=\dfrac{1}{25}\)

\(\Leftrightarrow x=\dfrac{1}{25}:\dfrac{13}{20}=\dfrac{1}{25}\cdot\dfrac{20}{13}=\dfrac{4}{65}\)

Vậy: \(x=\dfrac{4}{65}\)

Bài 2: 

a) Ta có: \(17\dfrac{2}{31}-\left(\dfrac{15}{17}+6\dfrac{2}{31}\right)\)

\(=17\dfrac{2}{31}-\dfrac{15}{17}-6\dfrac{2}{31}\)

\(=11+\dfrac{2}{31}-\dfrac{15}{17}\)

\(=\dfrac{5366}{527}\)