17 - 2x = -15

2x = 17 - (-15)

2x = 32

x = 32 : 2

x = 16

--------

54 : (x + 2) = -6

x + 2 = 54 : (-6)

x + 2 = -9

x = -9 - 2

x = -11

--------

12.(3 - x) = 72

3 - x = 72 : 12

3 - x = 6

x = 3 - 6

x = -3

-------

-3(x + 5) + 18 = -27

-3(x + 5) = -27 - 18

-3(x + 5) = -45

x + 5 = -45 : (-3)

x + 5 = 15

x = 15 - 5

x = 10

-------

(x + 5)² = 9

x + 5 = 3 hoặc x + 5 = -3

*) x + 5 = 3

x = 3 - 5

x = -2

*) x + 5 = -3

x = -3 - 5

x = -8

Vậy x = -8; x = -2

--------

(3 - x)³ = 27

(3 - x)³ = 3³

3 - x = 3

x = 3 - 3

x = 0

=00

- 3\(x\) + 24  = -24

  3\(x\)          = 24 + 24

   3\(x\)          = 48

     \(x\)           = 48 : 3

     \(x\)           = 16

\(24+3\times\left(5-x\right)=27\)

\(3\times\left(5-x\right)=3\)

\(5-x=1\)

\(x=5-1\)

\(x=4\)

a: =>5-x=-23

=>x=5+23=28

b: =>x-3-x+7-25+x=54

=>x-21=54

=>x=75

c: =>7-9x-2x+4=-5x-35+27-25=-5x-37

=>-11x+3=-5x-37

=>-6x=-40

=>x=20/3

a) \(10-x-5=\left(-5\right)-7-11\)

\(\Rightarrow5-x=-23\)

\(\Rightarrow x=5+23\)

\(\Rightarrow x=28\)

b) \(\left(x-3\right)-\left(x+17-24\right)-\left(25-x\right)=24-\left(-30\right)\)

\(\Rightarrow x-3-x-17+24-25+x=54\)

\(\Rightarrow x-21=54\)

\(\Rightarrow x=54+21\)

\(\Rightarrow x=75\)

c) \(\left(7-9x\right)-\left(2x-4\right)=-\left(5x+35\right)-\left(-27\right)-25\)

\(\Rightarrow7-9x-2x+4=-5x-35+27-25\)

\(\Rightarrow11-11x=-5x-33\)

\(\Rightarrow-11x+5x=-33-11\)

\(\Rightarrow-6x=-22\)

\(\Rightarrow x=\dfrac{22}{6}=\dfrac{11}{3}\)

a. 
10-x-5 = (-5) - 7 -11
=>5-x = 0
=>x=5
b
(x-3) - (x+17-24) - (25-x) = 24 - (-30)
=>x - 3 - x - 17 + 24 - 25 - x = 24 + 30
=>-x - 21 = 54
=>-x = 75
=>x = -75
c
(7 - 9x) - (2x - 4) = - (5x + 35) - (-27) - 25
=>7-9x - 2x + 4 = -5x - 35 + 27 - 35
=>11 - 11x + 5x = -43
=>16x = 11 + 43
=>16x = 54
=>x=4

=> 3(5-x)=3

=> 5-x=1

=> x=4

a) 3(x - 2) + 150 = 204

=> 3(x - 2)          = 204 - 150

=>3(x - 2)           = 54

=>  x - 2             = 54 : 3

=>  x - 2             = 18

=>  x                  = 18 + 2

=>  x                  = 20

b) (x - 13) : 5 = 12

=> x - 13       = 12 x 5

=> x - 13       = 60

=> x              = 60 + 13

=> x              = 73

3 ( x - 2 ) + 150 = 204

\(3\left(x-3\right)=54\)

\(\left(x-3\right)=18\)

\(x=21\)

( x - 13 ) : 5 = 12

\(x-13=60\)

\(x=73\)

24 + 3 ( 5 - x ) =27

\(3\left(5-x\right)=3\)

\(5-x=1\)

\(x=4\)

3 ( x - 2 ) + 150 = 204

<=> x-2=(204-150):3

<=> x-2=18

<=> x=20

( x - 13 ) : 5 = 12

<=> x-13=60

<=> x=73

\(24+3x\left(5-x\right)=27\)

\(3x\left(5-x\right)=27=24=3\)

\(5-x=3:3=1\)

\(x=5-1=4\)

24 + 3 * ( 5 - x ) = 27

27 * ( 5- x ) = 27

5- x = 27 : 27

5 - x = 1

x = 5- 1

x = 4

\(24+3X\left(5-x\right)=27\)

            \(3X\left(5-x\right)=27-24\)

             \(3X\left(5-x\right)=3\)

                    \(\left(5-x\right)=3:3\)

                    \(\left(5-x\right)=1\)

                                \(x=5-1\)

                                \(x=4\)

a)27-x/15=5/3

=>27-x/15=25/15

=>27-x=25

=>x=27-25

=>x=2

Vậy x = 2

b)5+x/7 = 24/21

=>5+x/7=8/7

=>5+x=8

=>x=8-5

=>x=3

Vậy x= 3 

27 - \(\frac{x}{15}\) = \(\frac{5}{3}\)

       \(\frac{x}{15}\) = 27 - \(\frac{5}{3}\)

        \(\frac{x}{15}\) = \(\frac{76}{3}\)

Phần b lm tương tự nha !!