a, 7\(x\).(\(x\) - 10) = 0

   \(\left[{}\begin{matrix}7x=0\\x-10=0\end{matrix}\right.\)

    \(\left[{}\begin{matrix}x=0\\x=10\end{matrix}\right.\)

Vậy \(x\in\) {0; 10}

b, 17.(3\(x\) - 6).(2\(x\) - 18) = 0

    \(\left[{}\begin{matrix}3x-6=0\\2x-18=0\end{matrix}\right.\)

    \(\left[{}\begin{matrix}3x=6\\2x-18=0\end{matrix}\right.\)

     \(\left[{}\begin{matrix}x=6:3\\x=18:2\end{matrix}\right.\)

       \(\left[{}\begin{matrix}x=2\\x=9\end{matrix}\right.\)

c, (4 - 2\(x\)).(\(x\) - 3) = 0

    \(\left[{}\begin{matrix}4-2x=0\\x-3=0\end{matrix}\right.\)

    \(\left[{}\begin{matrix}2x=4\\x=3\end{matrix}\right.\)

    \(\left[{}\begin{matrix}x=4:2\\x=3\end{matrix}\right.\)

     \(\left[{}\begin{matrix}x=2\\x=3\end{matrix}\right.\)

    Vậy \(x\in\) {2; 3}

\(2x\left(x+4\right)-2x^2-6=18\)

\(2x^2+8x-2x^2=18+6\)

\(8x=24\)

\(x=3\)

a) ta có: \(-6x=18\)

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

\(\Rightarrow x=-3\)

b) ta có: \(2x-\left(-3\right)=7\)

\(\Rightarrow2x+3=7\)

\(\Rightarrow2x=7-3\)

\(\Rightarrow2x=4\)

\(\Rightarrow x=2\)

c) ta có: \(\left(x-5\right)\left(x+6\right)=0\)

\(\Rightarrow\orbr{\begin{cases}x-5=0\\x+6=0\end{cases}\Rightarrow\orbr{\begin{cases}x=5\\x=-6\end{cases}}}\)

Vậy....

hok tốt!!

\(a,-6x=18\)

<=>\(x=18:\left(-6\right)\)

<=>\(x=-3\)

\(b,2x-\left(-3\right)=7\)

<=>\(2x+3=7\)

<=>\(2x=4\)

<=>\(x=2\)

\(c,\left(x-5\right)\left(x+6\right)=0\)

<=>\(\orbr{\begin{cases}x-5=0\\x+6=0\end{cases}}\)

<=>\(\orbr{\begin{cases}x=5\\x=-6\end{cases}}\)

A) -6x=18

        x=18:(-6)

        x=-3

Vậy x=-3

B) 2x -(-3)=7

     2x+3=7

     2x=7-3

     2x=4

       x=4:2

       x=2

vậy x=2

C) (x-5)(x+6)=0

* x-5=0            * x+6=0

      x=0+5              x=0-6

      x=5                  x=-6

Vậy x=5 hoặc x=-6

1.     Giải:

Do \(5x+13B\in\left(2x+1\right)\Rightarrow5x+13⋮2x+1.\)

 \(\Rightarrow2\left(5x+13\right)⋮2x+1\Rightarrow10x+26⋮2x+1.\)

 \(\Rightarrow5\left(2x+1\right)+21⋮2x+1.\)

Do 5(2x+1)⋮2x+1⇒ Ta cần 21⋮2x+1.

⇒ 2x+1 ϵ B(21)=\(\left\{1;3;7;21\right\}.\)

Ta có bảng:

Vậy xϵ\(\left\{0;1;3;10\right\}.\)

2. Giải:

Do (2x-18).(3x+12)=0.

⇒ 2x-18=0             hoặc             3x+12=0.

⇒ 2x     =18                               3x       =-12.

⇒   x     =9                                   x       =-4.

Vậy xϵ\(\left\{-4;9\right\}.\)

3. S= 1-2-3+4+5-6-7+8+...+2021-2022-2023+2024+2025.

S= (1-2-3+4)+(5-6-7+8)+...+(2021-2022-2023+2024)+2025 Có 506 cặp.

S= 0 + 0 + ... + 0 + 2025.

⇒S= 2025.

a, x=89

b, x=3

c, x=73

k minh nha

a. 45 . ( 91 - x ) = 90 

=> 91 - x          = 90 : 45 

=> 91 - x          = 2

=>       x           = 91 - 2 

=>       x           = 89 

b. ( 2x - 6 ) ( 3x - 18 ) = 0 

=> 2x - 6 = 0 hoặc 3x - 18 = 0 

Với  2x - 6 = 0 

=> 2x       = 0 + 6 

=> 2x       = 6 

=>   x      = 6 : 2 

=>   x      = 3 

Với 3x - 18 = 0 

=> 3x         = 0 +1 8 

=> 3x         = 18 
=>   x         = 18 : 3 

=>   x        = 6 

c. 5x + 73.21 = 73.26 

=> 5x           = 73.26 - 73.21

=> 5x          = 73 . ( 26 -21)

=> 5x         = 73 . 5 

=> 5x         = 365

=>   x        = 365 : 5 

=>    x       = 73

a)45x(91-x)=90

   90:45     =91-x

     2          91-x

     x=91-2=89.

c)5x+73x21=73x26

   5x+1533=1898

   5x         =1898-1533=365

   x           =75

a. -6x=18

\(\Rightarrow x=18:\left(-6\right)\)

\(\Rightarrow x=-3\)

Vậy x=-3

b,2x-(-3)=7

\(\Rightarrow2x=7+\left(-3\right)\)

\(\Rightarrow2x=4\)

\(\Rightarrow x=4:2\)

\(\Rightarrow x=2\)

Vậy x=2

c,(x-5)(x+6)=0

\(\Rightarrow\orbr{\begin{cases}x-5=0\\x+6=0\end{cases}}\)

\(\Rightarrow\orbr{\begin{cases}x=0+5\\x=0-6\end{cases}}\)

\(\Rightarrow\orbr{\begin{cases}x=5\\x=-6\end{cases}}\)

Vậy \(\orbr{\begin{cases}x=5\\x=-6\end{cases}}\)

- 6x = 18

x = 18 : ( - 6 )

x = -  3

a) -6x = 18

x = 18 : ( - 6 )

x = -3 

b) 2x - ( - 3 ) = 7

2x = 7 + ( - 3 )

2x = 4

x = 4 : 2

x = 2

c) \(\left(x-5\right)\left(x+6\right)=0\)

\(\Rightarrow\orbr{\begin{cases}x-5=0\\x+6=0\end{cases}\Rightarrow\orbr{\begin{cases}x=5\\x=-6\end{cases}}}\)

vậy x = 5 hoặc x = - 6

x + 18 = 6 - 2x

x + 2x = 6 - 18

3x = - 12

x = -4 

=.= hk tốt!!

x+2x = 6 - 18

3x = -12

x = -12 : 3

x = -4

Vậy......