1)  10 - 3 ( x - 1 ) = -5

      3 ( x - 1 ) = 10 - ( - 5 )

      3 ( x - 1 ) =  15

          x - 1   = 15 : 3

          x - 1   = 5

         x         = 5 + 1

        x         = 6

2) 3x + 75 = - 15

    3x        = - 15 - 75

    3x        = - 90

      x       = -90 : 3

     x        = -30

4)  12 - ( x - 7 ) = - 8

             x - 7   = 12 - (- 8 )

             x - 7   = 20

             x        = 20 + 7

            x         = 27

5)  x + 75 = 15

    x         = 15 - 75

    x         = -60

7)  2x + 18 = 10

     2x        = 10 - 18

     2x        = -8

       x        = - 8 : 2

       x       = -4

8)  26 - 3x = 5

            3x = 26 - 5

            3x = 21

              x  = 21: 3

              x = 7

9) x - 12 = - 15

    x       = -15 + 12

   x         =-3

 10 ) 24 - 2 ( x + 5 ) = 38

              2 ( x+ 5 )  = 24 - 38

              2 ( x + 5 ) = - 14

                  x + 5    = -14 : 2

                  x + 5    = -7

                  x          = -7 - 5

                  x          = -12

còn là bạn tự làm tiếp nhé ! bạn gửi nhiều cầu qua bạn chỉ nên gửi ít một thời như vậy khó có thể giải làm bạn ạ!

25 - 5 (3- x) = 15 

25 - 5 (3-x) = 15  

      5 (3-x) = 25 -15 

      5 (3-x) = 10 

     3 - x = 10 : 5 

    3 - x = 2 

         x = 3 - 2 

          x = 1

a) 42 - x = 5

x = 42 - 5

x = 37

b) 15.(x + 4) = 75

x + 4 = 75 : 15

x + 4 = 5

x = 5 - 4

x = 1

d) x + 18 = 12

x = 12 - 18

x = -6

e) 2x - 15 = -19

2x = (-19) + 15

2x = -4

x = -4 : 2

x = -2

f) 36 : (x^3 - 12) = -3

x^3 - 12 = 36 : (-3)

x^3 - 12 = -12

x^3 = 0

=> x = 0

g)x + 15 = 35

x = 35 - 15

x = 20

h) 2x - 13 = 3^2

2x - 13 = 9

2x = 9 + 13

2x = 22

x = 22 : 2

x = 11

a) 42-x=5

         x=42-5

         x= 37

b)15*(x+4)=75

        x+4=75:15

        x+4=5

        x    =5-4

       x     = 1

a) 42 - x = 5

x = 42 - 5

x = 37

b) 15.(x + 4) = 75

x + 4 = 75 : 15

x + 4 = 5

x = 5 - 4

x = 1

d) x + 18 = 12

x = 12 - 18

x = -6

e) 2x - 15 = -19

2x = (-19) + 15

2x = -4

x = -4 : 2

x = -2

f) 36 : (x^3 - 12) = -3

x^3 - 12 = 36 : (-3)

x^3 - 12 = -12

x^3 = 0

=> x = 0

g)x + 15 = 35

x = 35 - 15

x = 20

h) 2x - 13 = 3^2

2x - 13 = 9

2x = 9 + 13

2x = 22

x = 22 : 2

x = 11

1: \(=75\left(27+25-2\right)=75\cdot50=3750\)

2: \(=15\left(23+37\right)+55=15\cdot60+55=955\)

3: \(=36\cdot14+36\cdot17+36\cdot69\)

\(=36\cdot100=3600\)

4: \(=200\cdot\left(32+68\right)=200\cdot100=20000\)

a) 6x + 15 = 75

6x = 75 - 15

6x = 60

x = 60 : 6

x = 10

b) x - 12 = (-27)

x = (-27) + 12

x = -15

c) 23 + (x - 5) : 4 = 3⁸ : 3⁵

23 + (x - 5) : 4 = 3³

23 + (x - 5) : 4 = 27

23 + (x - 5) = 27 x 4

23 + (x - 5) = 108

x - 5 = 108 - 23

x - 5 = 85

x = 85 + 5

x = 90

\(3^x-15=12\\ \Rightarrow3^x=27\\ \Rightarrow x=3\)

\(5^{x-1}-12=13\\ \Rightarrow5^{x-1}=25\\ \Rightarrow x=3\)

\(3^{x-2}.9=81\\ \Rightarrow3^{x-2}=9\\ \Rightarrow x=4\)

\(3^{x+1}:9=3\\ \Rightarrow3^{x+1}=27\\ \Rightarrow x=2\)

\(2.x^3=16\\ \Rightarrow x^3=8\\ \Rightarrow x=2\)

\(75:x^2=3\\ \Rightarrow x^2=25\\ \Rightarrow x=\pm2\)

Câu cuối cộng trừ 5

Bài 1 bạn tự là nhé dễ lắm :))

Bài 2 :

Ta có :

\(4x-15=-75-x\)
\(\Leftrightarrow\)\(4x+x=-75+15\)

\(\Leftrightarrow\)\(5x=-60\)

\(\Leftrightarrow\)\(x=\frac{-60}{5}\)

\(\Leftrightarrow\)\(x=-12\)

Bài 3 :

Ta có :

\(12⋮\left(x-3\right)\)\(\Rightarrow\)\(\left(x-3\right)\inƯ\left(12\right)\)

Mà \(Ư\left(12\right)=\left\{1;-1;2;-2;3;-3;4;-4;6;-6;12;-12\right\}\)

Suy ra : ( lập bảng )

Vậy \(x\in\left\{4;2;5;1;6;0;7;-1;9;-3;15;-9\right\}\)

Chúc bạn học tốt 

`75/20 - x = 3/2 xx 10`

`15/4 - x = 15`

              `x  = 15/4 - 15`

              `x  = -45/4`

`(12 xx 15) - X xx 1/4 = 120 xx 1/4`

 `180 - X xx 1/4    = 30`

            `X xx 1/4   = 180-30`

            `X xx 1/4   = 150` 

                     `X     = 150 : 1/4`

                     `X      = 600`

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

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

\(x=-\dfrac{45}{4}\)

\(\left(12\times15\right)-\dfrac{1}{4}x=120\times\dfrac{1}{4}\)

\(180-\dfrac{1}{4}x=30\)

\(-\dfrac{1}{4}x=30-180\)

\(-\dfrac{1}{4}x=-150\)

\(-x=-150:\dfrac{1}{4}\)

\(-x=-150\times4\)

\(-x=-600\)

\(x=600\)

75/20 - X = 3/2 x 10

75/20 - X = 15

X = 75/20 - 15 

X = -45/4.

( 12 x 15  ) -  x X 1/4 = 120 x 1/4

( 12 x 15  ) -  x X 1/4 = 30

180 -  x X 1/4 = 30

180 -1/4X = 30

-1/4X = 30 - 180

-1/4X = -150

X = -150 x -4

X = 600.

a) \(2x-\left(x+25\right)-75=-12\)

\(\Rightarrow2x-\left(x+25\right)=63\)

\(\Rightarrow2x-x-25=63\)

\(\Rightarrow x=88\)

Vậy \(x=88\)

b) \(\left(x-12\right)-15=\left(120-18\right)-\left(20+x\right)\)

\(\Rightarrow\left(x-12\right)-15=102-20-x\)

\(\Rightarrow x-12-15=82-x\)

\(\Rightarrow x-27=82-x\)

\(\Rightarrow2x=27+82\)

\(\Rightarrow2x=109\)

\(\Rightarrow x=54,5\)

Vậy \(x=54,5\)

c) \(17-\left\{-x-\left[-x-\left(-x\right)\right]\right\}=-16\)

\(\Rightarrow17+x+x+x=-16\)

\(\Rightarrow17+3x=-16\)

\(\Rightarrow3x=-33\)

\(\Rightarrow x=-11\)

Vậy \(x=-11\)

d) \(x-\left\{\left[-x+\left(x+3\right)\right]-\left[\left(x+3\right)-\left(x-2\right)\right]\right\}=0\)

\(\Rightarrow x-\left\{\left[-x+x+3\right]-\left[x+3-x+2\right]\right\}=0\)

\(\Rightarrow x+2=0\)

\(\Rightarrow x=-2\)

Vậy \(x=-2\) (Câu này hơi tắt)

x=-36

x=11

x=100

x=14

x=-36

x=11

x=100

x=14

2: \(\Leftrightarrow\left(\dfrac{x+1}{12}-1\right)+\left(\dfrac{x+2}{13}-1\right)=\left(\dfrac{x+3}{14}-1\right)+\left(\dfrac{x+4}{15}-1\right)\)

=>x-11=0

=>x=11

3: \(\Leftrightarrow\left(\dfrac{x-85}{15}-1\right)+\left(\dfrac{x-74}{13}-2\right)+\left(\dfrac{x-67}{11}-3\right)+\left(\dfrac{x-64}{9}-4\right)=0\)

=>x-100=0

=>x=100