1a/ \(\left(15-x\right)+\left(x-12\right)=7-\left(-5+x\right)\)

=> \(\left(15-x\right)+\left(x-12\right)+\left(-5+x\right)=7\)

=> \(15-x+x-12-5+x=7\)

=> \(\left(15-12-5\right)-\left(x+x+x\right)=7\)

=> \(\left(15-12-5\right)-7=3x\)

=> \(3x=-2-7\)

=> \(3x=-9\)

=> \(x=\frac{-9}{3}=-3\)

b/ \(x-\left\{57-\left[42+\left(-23-x\right)\right]\right\}=13-\left\{47+\left[25-\left(32-x\right)\right]\right\}\)

=> \(x-57-42-23-x=13-47+25-32+x\)

=> \(x-x+x=13-47+25-32+57+42+23\)

=> \(x=\left(13+23\right)-\left(47+57\right)+\left(25+57\right)-\left(32+42\right)\)

=> \(x=36-104+82-74\)

=> \(x=-60\)

d/ \(\left(x-3\right)\left(2y+1\right)=7\)

Vì 7 là số nguyên tố nên ta có 2 trường hợp:

TH1: \(\hept{\begin{cases}x-3=1\\2y+1=7\end{cases}}\)=> \(\hept{\begin{cases}x=4\\y=3\end{cases}}\).

TH2: \(\hept{\begin{cases}x-3=7\\2y+1=1\end{cases}}\)=> \(\hept{\begin{cases}x=10\\y=0\end{cases}}\).

Các cặp (x, y) thoả mãn điều kiện: \(\left(4;3\right),\left(10;0\right)\).

Mình trả lời hai câu đầu trước nha!

1)

x= -6+2

x= -4

2)

=-5 x = 13 + (-3)

= -5 .x =10

x = 10 ÷ -5

x = -2

1) x - 2 = -6

x = -6 + 2

x = -4

2) -5 . x - ( -3 ) =13

-5 . x = 13 + ( -3 )

-5 . x = 10

x = 10 : ( -5 )

x = -2

A)

13 - 12 + 11 + 10 - 9 + 8 - 7 - 6 + 5 - 4 + 3 + 2 - 1

= 13 - ( 12 + 1 ) - ( 11 + 2 ) - ( 10 + 3 ) - ( 9 + 4 ) - ( 8 + 5 ) + ( 7 + 6 )

= 13  -      13     -       13     -       13      -     13      -      13     +      13

=        0             -                 0                -               0               +      13

= 13

13

1) x - 2 = -6

x = - 6 + 2

x = -4

2) -5x-(-3)=13

-5x+3=13

-5x=13-3=10

x=10:(-5)

x=-2

3) 15-(x-7)=21

15-x+7=21

15-x=21-7=14

x=15-14=1

4) 3x+17=2

3x=2-17=-15

x=-15:3=-5

5) 45-(x-9)=-35

45-x+9=-35

45-x=-35-9=-44

x=45-(-44)=89

6) -5+x=15

x=15-(-5)

x=20

7) 2x-(-17)=15

2x+17=15

2x=15-17=-2

x=-2:2=-1

ai giúp mk câu này với

8) \(\left|x-2\right|=3\\ \Rightarrow x-2=\pm3\)

+) x - 2 = 3

x = 5

+) x - 2 = -3

x = -1

\(\Rightarrow x\in\left\{5;-1\right\}\)

Các câu 9; 10; 12 tương tự câu 8; còn câu 11 tương tự câu 3; 5

Chúc bạn học tốt!

1) -5x - (-3) = 13

\(\Rightarrow-5x+3=13\)

\(\Rightarrow-5x=10\)

\(\Rightarrow x=-2\)

Vậy: \(x=-2\)

2) 15 - ( x - 7) = -21

\(\Rightarrow15-x+7=-21\)

\(\Rightarrow15+7-x=-21\)

\(\Rightarrow22-x=-21\)

\(\Rightarrow x=-22-21=-43\)

Vậy: \(x=-43\)

3) 45 - ( x - 9) = -35

\(\Rightarrow45-x+9=-35\)

\(\Rightarrow45+9-x=-35\)

\(\Rightarrow54-x=-35\)

\(\Rightarrow x=-54-35=-89\)

Vậy: \(x=-89\)

4)/x-2/=3\(\Rightarrow\)ta có 2 t/h:

t/h1: x-2=3\(\Rightarrow\)x=2+3=5

t/h2: x-2=-3\(\Rightarrow\)x=2+(-3)=-1

Vậy x=5 hoặc -1

Các bạn ơi trả lời giúp mk mấy câu hỏi này đi mk đang cần rất gấp ngay bây giờ?

Bài 1 : Tìm x

1/-(-30)-(-x)=-(+13)

⇒30+x=-13

⇒x=-13-30

⇒x=-43

2/ -(+12)-(+x)=-(+13)

⇒-12-x=-13

⇒x=-12+13

⇒x=1

3/ (-34)-x=-(-45)

⇒x=-34-45

⇒x=-79

4/-(-x)+(-15)=(-12)

⇒x-15=-12

⇒x=-12+15

⇒x=3

5/-15-x=-(-7)

⇒x=-15-7

⇒x=-22

Bài 2 : Tính

1/ (-15)-/-10/+/-9/-/-5/

=-15-10+9-5

=-21

2/14-(-13)-(-21)+(-32)

=14+13+21-32

=16

3/(-12)-(-17)-(-21)+(-32)

= -12+17+21-32

=-6

4/-/-14/ + /-10/-(-12)+(-8)

=-14+10+12-8

=0

5/-(-11)+(-15)+(+13)-21

=11-15+13-21

=-12

/ là phân số nha

11/13-(5/42-x)=(15/28-11/13)

11/13-(5/42-x)=-37/182

(5/42-x)=11/13+37/182

(5/42-x)=191/182

x=5/42-191/182

x=-254/273

vậy x=-254/273

bạn ấn vào chữ M nằm ngang ở dưới câu hỏi khi bạn trả lời là sẽ ấn được phân số nhé 

còn gửi câu trả lời cũng tương tự 

\(b,x+\frac{1}{3}=\frac{2}{5}-\left(-\frac{1}{3}\right)\)

\(< =>x+\frac{1}{3}=\frac{2}{5}+\frac{1}{3}\)

\(< =>x=\frac{1}{3}-\frac{1}{3}+\frac{2}{5}=\frac{2}{5}\)

\(c,\frac{2}{3}x+\frac{5}{7}=\frac{3}{10}\)

\(< =>\frac{2}{3}x=\frac{3}{10}-\frac{5}{7}=-\frac{29}{70}\)

\(< =>x=\frac{-29}{70}:\frac{2}{3}=-\frac{7}{140}\)

\(d,\frac{3}{7}-x=\frac{1}{4}-\left(-\frac{3}{5}\right)\)

\(< =>\frac{3}{7}-\frac{1}{4}-\frac{3}{5}=x\)

\(< =>x=-\frac{59}{140}\)

\(e,-\frac{21}{12}x+\frac{1}{3}=-\frac{2}{3}\)

\(< =>-\frac{21}{12}x=-\frac{2}{3}-\frac{1}{3}=-1\)

\(< =>x=\frac{12}{21}\)

a) 5.2² + (x + 3) = 5²

5.4 + x + 3 = 25

20 + x + 3 = 25

x + 23 = 25

x = 25 - 23

x = 2

b) 2³ + (x - 3²) = 5³ - 4³

8 + (x - 9) = 125 - 64

8 + x - 9 = 61

x - 1 = 61

x = 61 + 1

x = 62

c) 4.(x - 5) - 2³ = 2⁴.3

4x - 20 - 8 = 16.3

4x - 28 = 48

4x = 48 + 28

4x = 76

x = 76 : 4

x = 19

d) 5.(x + 7) - 10 = 2³.5

5x + 35 - 10 = 8.5

5x + 25 = 40

5x = 40 - 25

5x = 15

x = 15 : 5

x = 3

e) 7² - 7.(13 - x) = 14

49 - 91 + 7x = 14

7x - 42 = 14

7x = 14 + 42

7x = 56

x = 56 : 7

x = 8

a) \(5\cdot2^2+\left(x+3\right)=5^2\)

\(\Rightarrow x+3=5^2-5\cdot2^2\)

\(\Rightarrow x+3=25-5\cdot4\)

\(\Rightarrow x+3=5\)

\(\Rightarrow x=5-3\)

\(\Rightarrow x=2\)

b) \(2^3+\left(x-3^2\right)=5^3-4^3\)

\(\Rightarrow8+\left(x-9\right)=125-64\)

\(\Rightarrow8+x-9=61\)

\(\Rightarrow x-1=61\)

\(\Rightarrow x=61+1\)

\(\Rightarrow x=62\)

c) \(4\left(x-5\right)-2^3=2^4\cdot3\)

\(\Rightarrow4\left(x-5\right)=2^4\cdot3+2^3\)

\(\Rightarrow4\cdot\left(x-5\right)=16\cdot3+8\)

\(\Rightarrow4\cdot\left(x-5\right)=56\)

\(\Rightarrow x-5=56:4\)

\(\Rightarrow x-5=14\)

\(\Rightarrow x=19\)

d) \(5\left(x+7\right)-10=2^3\cdot5\)

\(\Rightarrow5\left(x+7\right)=8\cdot5+10\)

\(\Rightarrow5\left(x+7\right)=40+10\)

\(\Rightarrow5\left(x+7\right)=50\)

\(\Rightarrow x+7=10\)

\(\Rightarrow x=10-7\)

\(\Rightarrow x=3\)

e) \(7^2-7\left(13-x\right)=14\)

\(\Rightarrow7\left(13-x\right)=7^2-14\)

\(\Rightarrow7\left(13-x\right)=49-14\)

\(\Rightarrow7\left(13-x\right)=35\)

\(\Rightarrow13-x=5\)

\(\Rightarrow x=13-5\)

\(\Rightarrow x=8\)

f) \(5x-5^2=10\)

\(\Rightarrow5x=10+5^2\)

\(\Rightarrow5x=10+25\)

\(\Rightarrow5x=35\)

\(\Rightarrow x=\dfrac{35}{5}\)

\(\Rightarrow x=7\)

g) \(9x-2\cdot3^2=3^4\)

\(\Rightarrow9x=3^4+2\cdot3^2\)

\(\Rightarrow9x=81+2\cdot9\)

\(\Rightarrow9x=99\)

\(\Rightarrow x=\dfrac{99}{9}\)

\(\Rightarrow x=11\)

h) \(10x+2^2\cdot5=10^2\)

\(\Rightarrow10x=10^2-2^2\cdot5\)

\(\Rightarrow10x=100-4\cdot5\)

\(\Rightarrow10x=80\)

\(\Rightarrow x=\dfrac{80}{10}\)

\(\Rightarrow x=8\)

i) \(125-5\left(4+x\right)=15\)

\(\Rightarrow5\left(4+x\right)=125-5\)

\(\Rightarrow5\left(4+x\right)=120\)

\(\Rightarrow4+x=\dfrac{120}{5}\)

\(\Rightarrow4+x=24\)

\(\Rightarrow x=24-4\)

\(\Rightarrow x=20\)

j) \(2^6+\left(5+x\right)=3^4\)

\(\Rightarrow5+x=3^4-2^6\)

\(\Rightarrow5+x=81-64\)

\(\Rightarrow5+x=17\)

\(\Rightarrow x=17-5\)

\(\Rightarrow x=12\)

f) 5x - 5² = 10

5x - 25 = 10

5x = 10 + 25

5x = 35

x = 35 : 5

x = 7

g) 9x - 2.3² = 3⁴

9x - 2.9 = 81

9x - 18 = 81

9x = 81 + 18

9x = 99

x = 99 : 9

x = 11

h) 10x - 2².5 = 10²

10x - 4.5 = 100

10x - 20 = 100

10x = 100 + 20

10x = 120

x = 120 : 10

x = 12

i) 125 - 5.(4 + x) = 15

5.(4 + x) = 125 - 15

5.(4 + x) = 110

4 + x = 110 : 5

4 + x = 22

X = 22 - 4

x = 18

j) 2⁶ + (5 + x) = 3⁴

64 + 5 + x = 81

69 + x = 81

x = 81 - 69

x = 12