a) x = 0

b) x = -1

c) x  = -2

1. x + 2x = -36

=> 3x = -36

=> x = -36 : 3

=> x = -12

2. (2x + 3) \(⋮\)(x - 2)

=> (2x - 2) + 5 \(⋮\)(x - 2)

=> 2(x - 2) + 5 \(⋮\)(x - 2)

=> 5 \(⋮\)(x - 2)

=> x - 2 \(\in\)Ư(5) = {-5;-1;1;5}

=> x \(\in\){-3;1;3;7}

3. Khi đó a . (-b) = -132

4. -2(3x + 2) = 1² + 2² + 3²

=> -2(3x + 2) = 1 + 4 + 9

=> -2(3x + 2) = 14

=> 3x + 2 = 14 : (-2)

=> 3x+ 2 = -7

=> 3x = -7 - 2

=> 3x = -9

=> x = -9 : 3

=> x = -3

1/ \(x+2x=-36\)

\(\Rightarrow3x=-36\)

\(\Rightarrow x=-\frac{36}{3}\)

\(\Rightarrow x=-12\)

2/    \(\left(2x+3\right)⋮\left(x-2\right)\)

\(\Leftrightarrow\left(2x-4\right)+7⋮\left(x-2\right)\)

\(\Leftrightarrow2\left(x-2\right)+7⋮\left(x-2\right)\)

\(\Rightarrow7⋮\left(x-2\right)\)

\(\Rightarrow\left(x-2\right)\inƯ\left(7\right)\)

\(\Rightarrow x\inƯ\left(7-2\right)\)

\(\Rightarrow x\inƯ\left(5\right)\)

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

Vậy x nhỏ nhất để \(\left(2x-3\right)⋮\left(x-2\right)\) là -5

3/ Vì \(a\cdot b=32\)

\(\Rightarrow-a\cdot b=-\left(a\cdot b\right)=-32\)

4/ \(-2\left(3x+2\right)=1^2+2^2+3^2\)

\(\Leftrightarrow-6x-4=1+4+9\)

\(\Leftrightarrow-6x=14+4\)

\(\Leftrightarrow-6x=18\)

\(\Leftrightarrow x=\frac{18}{-6}\)

\(\Rightarrow x=3\)

a: =>-12<x<2y<-9

=>x=-11; y=-5

b: =>-7<3(x-1)<8

\(\Leftrightarrow3\left(x-1\right)\in\left\{-6;-3;0;3;6\right\}\)

\(\Leftrightarrow x-1\in\left\{2;1;0;-1;-2\right\}\)

hay \(x\in\left\{3;2;1;0;-1\right\}\)

a) \(-45:5.\left(-3-2x\right)=3\)

\(-9.\left(-3-2x\right)=3\)

\(-3-2x=\left(3:-9\right)\)

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

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

-2x=\(\dfrac{-10}{3}\)

\(x=\dfrac{-10}{3}:-2\)

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

b) 

3x - 28 = x + 36

<=> 3x - x = 36 + 28

<=> 2x = 64

<=> x = 32

Vậy x = 32

c) 

(-12)2.x = 56 + 10.13.x

144.x = 56 + 130.x

144x – 130 x = 56

14x = 56

x = 56: 14

x = 4

Vậy x = 4

a) -12 . x = 36

x = 36 : (-12)

x = -3

b) 3 . x - ( - 117 - 23 ) = 23

3 . x - (-140) = 23

3 . x + 140 = 23

3 . x = 23 - 140

3 . x = -117

x = -117 : 3

x = -39

Học Tốt !

a) -12 . x = 36

            x = - 12 - 36

            x = (- 12) + (- 36) = - 48

b) 3 . x - ( - 117 - 23 ) = 23

    3 . x - [ (- 117) + (- 23) ] = 23

    3 . x - (- 140) = 23

    3 . x               = 23 + (- 140) = (- 117)

         x               = (- 117) : 3

         x               = - 39

=>-(1+2+...+x)=-36

=>1+2+...+x=36

\(\Leftrightarrow x=8\)

-(1+2+...+x)=-36

=1+2+...+x=36

<-> x=8

a) {-2).x = -10 => x = (-10): (- 2) => x = 5.

b)  (-18). x = -36 => x = (-36): (-18) => x = 2.

c) 2.x + 1 = 3=>2x = 2 => x = l.

d) (-4).x + 5 = -15 => (-4)x = (-15) -5 => (-4) x = -20 => x = 5.

a) {-2).x = -10 => x = (-10): (- 2) => x = 5.

b)  (-18). x = -36 => x = (-36): (-18) => x = 2.

c) 2.x + 1 = 3=>2x = 2 => x = l.

d) (-4).x + 5 = -15 => (-4)x = (-15) -5 => (-4) x = -20 => x = 5.

a) (x: 8 - l).2 = 1.14 nên x : 8 - 1 = 7. Do đó x =  64.

b) (2x + 3).30 = 25.6 nên 2x + 3 = 5. Do đó x = 1.

c) 6.(2x - 7) = 9.(x - 3) nên 12x - 42 = 9x - 27.

Do đó 3x = 15. Vậy x =  5.

d) -7.(x + 27) = 6.(x + l) nên -7x - 189 = 6x + 6.

Do đó 13x = -195. Vậy x = -15.