1: 2*2*2*2*2*2=2^6

2: x*x*x*x=x^4

3: =7^4*6^4=42^4

4: =5^2*3^2*4^2=60^2

5: =2*3^2*5^5

6: =10^3*10^3=10^6

\(1,\\ x+\dfrac{1}{2}=-\dfrac{5}{3}\\ x=-\dfrac{5}{3}-\dfrac{1}{2}\\ x=-\dfrac{13}{6}\\ Vậyx=-\dfrac{13}{6}\)

\(2,\\ \dfrac{1}{3}-x=\dfrac{3}{5}\\ x=\dfrac{1}{3}-\dfrac{3}{5}\\ x=-\dfrac{4}{15}\\ Vậyx=-\dfrac{4}{15}\)

\(3,\\ 3-4+x=\dfrac{7}{2}\\ -1+x=\dfrac{7}{2}\\ x=\dfrac{7}{2}+1\\ x=\dfrac{9}{2}\\ Vậyx=\dfrac{9}{2}\)

\(4,\\ x-\dfrac{4}{3}=-\dfrac{7}{9}\\ x=-\dfrac{7}{9}+\dfrac{4}{3}\\ x=\dfrac{15}{27}\\ Vậyx=\dfrac{15}{27}\)

\(5,\\ x-\left(-\dfrac{7}{3}\right)=\dfrac{5}{6}\\ x=\dfrac{5}{6}-\dfrac{7}{3}\\ x=-\dfrac{27}{18}\\ Vậyx=-\dfrac{27}{18}\)

\(6,\\ x-\dfrac{1}{5}=\dfrac{9}{10}\\ x=\dfrac{9}{10}+\dfrac{1}{5}\\ x=\dfrac{11}{10}\\ Vậyx=\dfrac{11}{10}\)

\(7,\\ x+\dfrac{5}{12}=\dfrac{3}{8}\\ x=\dfrac{3}{8}-\dfrac{5}{12}\\ x=-\dfrac{1}{24}\\ Vậyx=-\dfrac{1}{24}\)

\(8,\\ x+\dfrac{5}{4}=\dfrac{7}{6}\\ x=\dfrac{7}{6}-\dfrac{5}{4}\\ x=-\dfrac{9}{24}\\ Vậyx=-\dfrac{9}{24}\)

\(9,\\ x-\dfrac{2}{7}=\dfrac{1}{35}\\ x=\dfrac{1}{35}+\dfrac{2}{7}\\ x=\dfrac{11}{35}\\ Vậyx=\dfrac{11}{35}\\ 10,\\ x-\dfrac{1}{5}=-\dfrac{7}{10}\\ x=-\dfrac{7}{10}+\dfrac{1}{5}\\ x=-\dfrac{1}{2}\\ Vậyx=-\dfrac{1}{2}\)

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Hướng dẫn giải:

a) 3 x (20 – 5)

Cách 1:

3 x (20 – 5) = 3 x 15 = 45

Cách 2:

3 x (20 – 5) = 3 x 20 – 3 x 5 = 60 – 15 = 45

b) 20 x (40 – 1)

Cách 1:

20 x (40 – 1) = 20 x 39 = 780

Cách 2:

20 x (40 – 1) = 20 x 40 – 20 x 1 = 800 – 20 = 780

a) -3.(x-5) + 6.(x+2) = 9

-3x + 15 + 6x + 12 = 9

3x + 27 = 9

3x = -18

x = -6

b) 7.(x-9) - 5.(6-x) = -6 + 11.x

7x - 63 - 30 + 5x = - 6 +  11.x

=> 12x - 11x = - 6 + 63 + 30

x = 87

c) 10.(x-7) - 8.(x+5) = 6.(-5) + 24

10x - 70 -8x - 40 = -6

2x - 110 = - 6

2x = 104

x = 52

\(-3\left(x-5\right)+6\left(x+2\right)=9\)

\(\Rightarrow-3x+15+6x+12=9\)

\(\Rightarrow-3x+6x=9-15-12\)

\(\Rightarrow3x=-18\)\(\Rightarrow x=-6\)

\(7\left(x-9\right)-5\left(6-x\right)=-6+11x\)

\(\Rightarrow7x-63-30+5x=-6+11x\)

\(\Rightarrow7x+5x-11x=-6+63+30\)

\(\Rightarrow x=-6+63+30=87\)

mik ko viết dấu dc mọi người thông cảm

tìm x à

tìm tổng của tất cả các số thỏa mãn

Giúp mk với!!!!

1) -10 < x < 10

Gọi tập hợp trên là A: Các phần tử của tập A là:

A = { -9;-8;-7;-6;-5;-4;-3;-2;-1;0;1;2;3;4;5;6;7;8;9}

Tổng các phần tử tập hợp A là: (-9) + (-8) + (-7) + (-6) + (-5) + (-4) + (-3) + (-2) + (-1) + 0 + 1 + 2 + 3 + 4 + 5 + 6 + 7 + 8 + 9

= [(-9) + 9] + [(-8) + 8] + [(-7) + 7] + [(-6) + 6] + [(-5) + 5] + [(-4) + 4] + [(-3) + 3] + [(-2) + 2] + [(-1) + 1]

= 0 + 0 + 0 + 0 + ... + 0 (9 số 0)

= 0

2) -5 ≤ x < 5

Gọi tập hợp trên là B, theo đề bài trên, tập hợp B có số phần tử là: 

B = {-5;-4;-3;-2;-1;0;1;2;3;4}

Tổng các phần tử của tập B là: (-5) + (-4) + (-3) + (-2) + (-1) + 0 + 1 + 2 + 3 + 4

= [(-4) + 4] + [(-3) + 3] + [(-2) + 2] + [(-1) + 1] + (-5)

= 0 + 0 + 0 + 0 + (-5)

= (-5)

1) 2(x + 5) + 3(x + 7) = 41
2x + 10 + 3x + 21 = 41
5x + 31 = 41
5x = 10
x = 2
6) 7(x - 1) + 5(3 - x) = 11x - 10
7x - 7 + 15 - 5x = 11x - 10
2x + 8 = 11x - 10
-9x = -18
x = 2

2) 5(x + 6) + 2(x - 3) = 38
5x + 30 + 2x - 6 = 38
7x + 24 = 38
7x = 14
x = 2

7) 4(2 + x) + 3(x - 2) = 12
8 + 4x + 3x - 6 = 12
7x + 2 = 12
7x = 10
x = 10/7

3) 7(5 + x) + 2(x - 10) = 15
35 + 7x + 2x - 20 = 15
9x + 15 = 15
9x = 0
x = 0

8) 5(2 + x) + 4(3 - x) = 10x - 15
10 + 5x + 12 - 4x = 10x - 15
x + 22 = 10x - 15
9x = 37
x = 37/9

4) 3(x + 4) + (8 - 2x) = 22
3x + 12 + 8 - 2x = 22
x + 20 = 22
x = 2

9) 7(x - 2) + 5(3 - x) = 11x - 6
7x - 14 + 15 - 5x = 11x - 6
2x + 1 = 11x - 6
-9x = -7
x = 7/9

5) 4(x + 5) + 3(7 - x) = 49
4x + 20 + 21 - 3x = 49
x + 41 = 49
x = 8

10) 5(3 - x) + 5(x + 4) = 6 + 4x
15 - 5x + 5x + 20 = 6 + 4x
35 = 6 + 4x
4x = 29
x = 29/4

1) 2(x + 5) + 3(x + 7) = 41

2x + 10 + 3x + 21 = 41

5x + 31 = 41

5x = 41 - 31

5x = 10

x = 10 : 5

x = 2

2) 5(x + 6) + 2(x - 3) = 38

5x + 30 + 2x - 6 = 38

7x + 24 = 38

7x = 38 - 24

7x = 14

x = 14 : 7

x = 2

3) 7(5 + x) + 2(x - 10) = 15

35 + 7x + 2x - 20 = 15

9x + 15 = 15

9x = 15 - 15

9x = 0

x = 0

4) 3(x + 4) + (8 - 2x) = 22

3x + 12 + 8 - 2x = 22

x + 20 = 22

x = 22 - 20

x = 2

5) 4(x + 5) + 3(7 - x) = 49

4x + 20 + 21 - 3x = 49

x + 41 = 49

x = 49 - 41

x = 8

6) 7(x - 1) + 5(3 - x) = 11x - 10

7x - 7 + 15 - 5x = 11x - 10

2x - 11x + 8 = -10

-9x = -10 - 8

-9x = -18

x = -18 : (-9)

x = 2

7) 4(2 + x) + 3(x - 2) = 12

8 + 4x + 3x - 6 = 12

7x + 2 = 12

7x = 12 - 2

7x = 10

x = 10/7

8) 5(2 + x) + 4(3 - x) = 10x - 15

10 + 5x + 12 - 4x = 10x - 15

10x - 15 = x + 22

10x - x = 22 + 15

9x = 37

x = 37/9

9) 7(x - 2) + 5(3 - x) = 11x - 6

7x - 14 + 15 - 5x = 11x - 6

11x - 6 = 2x + 1

11x - 2x = 1 + 6

9x = 7

x = 7/9

10) 5(3 - x) + 5(x + 4) = 6 + 4x

15 - 5x + 5x + 20 = 6 + 4x

6 + 4x = 35

4x = 35 - 6

4x = 29

x = 29/4

1/ \(x+\dfrac{1}{2}=\dfrac{-5}{3}\)

\(x=\dfrac{-5}{3}-\dfrac{1}{2}\)

\(x=\dfrac{-10}{6}-\dfrac{3}{6}\)

Vậy \(x=\dfrac{-13}{6}\)

2/\(\dfrac{1}{3}-x=\dfrac{3}{5}\)

\(-x=\dfrac{3}{5}-\dfrac{1}{3}\)

\(-x=\dfrac{9}{15}-\dfrac{5}{15}\)

\(-x=\dfrac{4}{15}\)

Vậy \(x=\dfrac{-4}{15}\)

3/ \(3-4+x=\dfrac{7}{2}\)

\(-4+x=\dfrac{7}{2}-3\)

\(-4+x=\dfrac{7}{2}-\dfrac{6}{2}\)

\(-4+x=\dfrac{1}{2}\)

\(x=\dfrac{1}{2}+4\)

\(x=\dfrac{1}{2}+\dfrac{8}{2}\)

Vậy \(x=\dfrac{9}{2}\)

4/ \(x-\dfrac{4}{3}=\dfrac{-7}{9}\)

\(x=\dfrac{-7}{9}+\dfrac{4}{3}\)

\(x=\dfrac{-7}{9}+\dfrac{12}{9}\)

Vậy \(x=\dfrac{5}{9}\)

5/ \(x-\dfrac{-7}{2}=\dfrac{5}{6}\)

\(x=\dfrac{5}{6}-\dfrac{7}{2}\)

\(x=\dfrac{5}{6}-\dfrac{21}{6}\)

Vậy \(x=\dfrac{-16}{6}=\dfrac{-8}{3}\)

6/ \(x-\dfrac{1}{5}=\dfrac{9}{10}\)

\(x=\dfrac{9}{10}+\dfrac{1}{5}\)

\(x=\dfrac{9}{10}+\dfrac{2}{10}\)

Vậy \(x=\dfrac{11}{10}\)

7/ \(x+\dfrac{5}{12}=\dfrac{3}{8}\)

\(x=\dfrac{3}{8}-\dfrac{5}{12}\)

\(x=\dfrac{9}{24}-\dfrac{10}{24}\)

Vậy \(x=\dfrac{-1}{24}\)

8/ \(x+\dfrac{5}{4}=\dfrac{7}{6}\)

\(x=\dfrac{7}{6}-\dfrac{5}{4}\)

\(x=\dfrac{14}{12}-\dfrac{15}{12}\)

Vậy \(x=\dfrac{-1}{12}\)

9/ \(x-\dfrac{2}{7}=\dfrac{1}{35}\)

\(x=\dfrac{1}{35}+\dfrac{2}{7}\)

\(x=\dfrac{1}{35}+\dfrac{10}{35}\)

Vậy \(x=\dfrac{11}{35}\)

10 /\(x-\dfrac{1}{5}=\dfrac{-7}{10}\)

\(x=\dfrac{-7}{10}+\dfrac{1}{5}\)

\(x=\dfrac{-7}{10}+\dfrac{2}{10}\)

Vậy \(x=\dfrac{-5}{10}=\dfrac{-1}{2}\)

a,  3^9:3^2=3^7

b,  (3/5)^15:(3/5)^10=(3/5)^5

c,  (5.3.3)^10.5^10 / (5.5.3)^10=5^10.3^10.3^10.5^10 / 5^10.5^10.3^10=5^20.3^20 / 5^20.3^10=3^10

a, .. . = 270

b, .. . = 135

c, 270 : 135 = 2

a) 1 . 5 . 6 + 2 . 10 . 12 = A 
     1 . 5 . 6 + 1 . 2 . 5 . 2 . 6 . 2 = A 
     1 . 5 . 6 . ( 1 + 2. 2 . 2 )       = A 
            30 . 9                           = A 
                      270   = A 
b) 1 . 3 . 5 + 2 . 6 . 10 = B 
      1 . 3 . 5 + 1 . 2 . 3 . 2 . 5 . 2 = B 
      1 . 3 . 5 . ( 1 + 2 . 2 . 2 )   = B 
            15 . 9  = B 
               135  = B 
c) A : B = A/B