Bài 2: 

a: \(\Leftrightarrow\left(x-2\right)\left(x+1\right)=0\)

\(\Leftrightarrow\left[{}\begin{matrix}x=2\\x=-1\end{matrix}\right.\)

     \(x^2-2x+1=25\)

\(\Leftrightarrow\)\(\left(x-1\right)^2=25\)

\(\Leftrightarrow\)\(\orbr{\begin{cases}x-1=5\\x-1=-5\end{cases}}\)

\(\Leftrightarrow\)\(\orbr{\begin{cases}x=6\\x=-4\end{cases}}\)

Vậy....

b)  \(3\left(x-1\right)^2-3x\left(x-5\right)=1\)

\(\Leftrightarrow\)\(3x^2-6x+3-3x^2+15x=1\)

\(\Leftrightarrow\)\(9x=-2\)

\(\Leftrightarrow\)\(x=-\frac{2}{9}\)

Vậy...

Cam on ban <3

a: \(\Leftrightarrow5^{10}⋮5^{2x}\)

\(\Leftrightarrow2x\in\left\{1;2;5;10\right\}\)

hay \(x\in\left\{\dfrac{1}{2};1;\dfrac{5}{2};5\right\}\)

b: \(\Leftrightarrow\left(2x-1;y-2\right)\in\left\{\left(1;35\right);\left(5;7\right);\left(7;5\right);\left(35;1\right)\right\}\)

hay \(\left(x,y\right)\in\left\{\left(1;37\right);\left(3;9\right);\left(4;7\right);\left(18;3\right)\right\}\)

Tìm x thuoc z:

1) \(26-\left|x+9\right|=-13\)

\(\Leftrightarrow\left|x+9\right|=26-\left(-13\right)\)

\(\Leftrightarrow\left|x+9\right|=39\)

\(\Leftrightarrow\left[{}\begin{matrix}x+9=39\\x+9=-39\end{matrix}\right.\)

\(\Leftrightarrow\left[{}\begin{matrix}x=39-9=30\\x=-39-9=-48\end{matrix}\right.\)

Vậy: \(x\in\left\{30;-48\right\}\)

2) \(\left|x+7\right|-13=25\)

\(\Leftrightarrow\left|x+7\right|=25+13=38\)

\(\Leftrightarrow x+7\in\left\{38;-38\right\}\)

\(\Leftrightarrow x\in\left\{31;-45\right\}\)

Vậy:.................

tim x biet

\(1)123-3.\left(x+4\right)=23\)

\(\Leftrightarrow3\left(x+4\right)=123-23\)

\(\Leftrightarrow3\left(x+4\right)=100\)

\(\Leftrightarrow x+4=\frac{100}{3}\)

\(\Leftrightarrow x=\frac{100}{3}-4=\frac{100-12}{3}=\frac{88}{3}\)

Vậy:................

2) Tương tự

2346 : (25 + x) = 23

=> 25 + x = 2346 : 23 = 102

=> x = 102 - 25  =  77

Vậy x = 77

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

=> 2x - 6 + 5x + 20 = 49

=> 7x + (20 - 6) = 49

=> 7x + 14 = 49

=> 7x = 49 - 14 = 35

=> x = 35 : 7 = 5

Vậy x = 5

(2x-10)³ . 25¹⁰⁰⁷ = \(5^2.5^{2015}\)

\(\left(2x-10\right)^3.5^{2014}=5^{2014}.5^3\)

\(\left(2x-10\right)^3=5^3\)

2x - 10 = 5

=> 2x = 5 + 10 = 15

=> x = 15  2 = 7,5

Vậy x = 7,5

1. a. 2346:(25+x)=23

=> 25+x=2346:23

=> 25+x=102

=> x=102-25

=> x=77

b. 2(x-3)+5(x+4)=49

=> 2x-6+5x+20=49

=> 7x+14=49

=> 7x=49-14

=> 7x=35

=> x=35:7

=> x=5

c. (2x-10)³.25¹⁰⁰⁷=5².5²⁰¹⁵

=> (2x-10)³.(5²)¹⁰⁰⁷=5²⁰¹⁷

=> (2x-10)³.5²⁰¹⁴=5²⁰¹⁷

=> (2x-10)³=5²⁰¹⁷:5²⁰¹⁴

=> (2x-10)³=5³

=> 2x-10=5

=> 2x=5+10

=> 2x=15

=> x=15:2

=> x=7,5

Bài 1: Tìm x, biết     

a )24-(36+5)=x                              b)14-21=(13-x)-(15+8)                         

    24-41=x                                      (13-x)-23=-7 

    x=-17                                          13-x=(-7)+23

Vậy x=-17                                        13-x=16

                                                        x=13-16

                                                        x=-3                 Vậy x=-3

Bài 2:Tìm x, biết

a)17-x=-25+(-16+9)                           b)3x-21=-19-(-2x)                

   17-x=-25+(-7)                                   3x-21=-19+2x

    17-x=-32                                         3x-2x=-19+21

     x=17-(-32)                                       x=4

     x=49                                                    Vậy x=4

Vậy x=49

Bài 1:

a. 24 - (36+5) = x

=> 24 - 41 = x

=> -17 = x

=> x = -17

b. 14 - 21 = (13 - x) - (15 + 8)

=> -7 = 13 - x - 23

=> -7 - 13 + 23 = -x

=> 3 = -x

=> x = -3

Bài 2:

a. 17 - x = -25 + (-16 + 9)

=> 17 - x = -25 + (-7)

=> 17 - x = -32

=> 17 + 32 = x 

=> x = 49

b. 3x - 21 = -19 - (-2x)

=> 3x - 21 = -19 + 2x

=> 3x - 2x = -19 + 21

=> x = 2

a) = (3x +1)² =0 

3x+1 =0

x = -1/3

b) = (5x)² -2² =0

(5x+2)(5x-2) = 0

5x+2 =0

x = -2/5

5x -2  =0

x= 2/5

xem đi rui lam tip

a) 9x² + 6x + 1 = 0  => (3x)² + 2 x 3x + 1 = 0  => (3x + 1)²  = 0  => 3x + 1 = 0  => x = \(\frac{-1}{3}\)

b) 25x² = 4  => x² = 4 : 25  => x² = 0,16  => x = 0,4 hoặc x = -0,4

c) 8 - 125x³ = 0  => 125x³ = 8  => x³ = 8 : 125  => x³ = \(\frac{8}{125}\)=> x = \(\frac{2}{5}\)