Bài 1:

2² x 567 - 356 x 2² + 2² x 789

= 2² x ( 567 - 356 + 789 )

= 4 x 1000

= 4000 

Bài 2:

12x - 10x = 5⁸ + 201⁰

2x = 390626

x = 390626 : 2 

x = 195313

\(1,\Leftrightarrow x\left(x-9\right)=0\Leftrightarrow\left[{}\begin{matrix}x=9\\x=0\end{matrix}\right.\\ 2,\Leftrightarrow x^2-4x-x^2=7\Leftrightarrow-4x=7\Leftrightarrow x=-\dfrac{7}{4}\\ 3,\Leftrightarrow3x+2x-10=5\Leftrightarrow5x=15\Leftrightarrow x=3\\ 4,\Leftrightarrow\left(5x-1\right)\left(5x+1\right)=0\Leftrightarrow\left[{}\begin{matrix}x=\dfrac{1}{5}\\x=-\dfrac{1}{5}\end{matrix}\right.\\ 5,\Leftrightarrow\left(x-2\right)\left(3x-5\right)=0\Leftrightarrow\left[{}\begin{matrix}x=2\\x=\dfrac{5}{3}\end{matrix}\right.\\ 6,\Leftrightarrow\left(x-7\right)\left(3x+4\right)=0\Leftrightarrow\left[{}\begin{matrix}x=7\\x=-\dfrac{4}{3}\end{matrix}\right.\)

\(7,\Leftrightarrow\left(2x-3\right)\left(2x+3\right)=0\Leftrightarrow\left[{}\begin{matrix}x=\dfrac{3}{2}\\x=-\dfrac{3}{2}\end{matrix}\right.\\ 8,\Leftrightarrow\left(x-4\right)\left(10x+2\right)=0\Leftrightarrow\left[{}\begin{matrix}x=-\dfrac{1}{5}\\x=4\end{matrix}\right.\\ 9,\Leftrightarrow2x^2-5x-2x^2=0\Leftrightarrow x=0\\ 10,\Leftrightarrow2x\left(x-2\right)=0\Leftrightarrow\left[{}\begin{matrix}x=0\\x=2\end{matrix}\right.\\ 11,\Leftrightarrow\left(4x-3\right)\left(3-2x\right)=0\Leftrightarrow\left[{}\begin{matrix}x=\dfrac{3}{4}\\x=\dfrac{3}{2}\end{matrix}\right.\\ 12,\Leftrightarrow2x^2-10x-2x^2=3\Leftrightarrow-10x=3\Leftrightarrow x=-\dfrac{3}{10}\)

\(1,\Leftrightarrow x\left(x-9\right)=0\\ \Leftrightarrow\left[{}\begin{matrix}x=0\\x=9\end{matrix}\right.\\ 2,\Leftrightarrow x^2-4x-x^2=7\\ \Leftrightarrow-4x=7\\ \Leftrightarrow x=\dfrac{-7}{4}\\ 3,\Leftrightarrow3x+2x-10=5\\ \Leftrightarrow5x=15\\ \Leftrightarrow x=3\\ 4,\Leftrightarrow\left(5x-1\right)\left(5x+1\right)=0\\ \Leftrightarrow\left[{}\begin{matrix}x=\dfrac{1}{5}\\x=-\dfrac{1}{5}\end{matrix}\right.\)

\(5,\Leftrightarrow\left(x-2\right)\left(3x-5\right)=0\\ \Leftrightarrow\left[{}\begin{matrix}x=2\\x=\dfrac{5}{3}\end{matrix}\right.\\ 6,\Leftrightarrow\left(3x+4\right)\left(x-7\right)=0\\ \Leftrightarrow\left[{}\begin{matrix}x=-\dfrac{4}{3}\\x=7\end{matrix}\right.\\ 7,\Leftrightarrow\left(2x-3\right)\left(2x+3\right)=0\\ \Leftrightarrow\left[{}\begin{matrix}x=\dfrac{3}{2}\\x=-\dfrac{3}{2}\end{matrix}\right.\)

\(8,\Leftrightarrow10x\left(x-4\right)+2\left(x-4\right)=0\\ \Leftrightarrow\left(x-4\right)\left(10x+2\right)=0\\ \Leftrightarrow\left[{}\begin{matrix}x=4\\x=-\dfrac{1}{5}\end{matrix}\right.\\ 9,\Leftrightarrow2x^2-5x-2x^2=0\\ \Leftrightarrow-5x=0\\ \Leftrightarrow x=0\\ 10,\Leftrightarrow2x\left(x-2\right)=0\\ \Leftrightarrow\left[{}\begin{matrix}x=0\\x=2\end{matrix}\right.\)

\(11,\Leftrightarrow\left(2x-3\right)\left(4x-3\right)=0\\ \Leftrightarrow\left[{}\begin{matrix}x=\dfrac{3}{2}\\x=\dfrac{3}{4}\end{matrix}\right.\\ 12,\Leftrightarrow2x^2-10x-2x^2=3\\ \Leftrightarrow-10x=3\\ \Leftrightarrow x=-\dfrac{3}{10}\)

1) \(x^2-9x=0\Rightarrow x\left(x-9\right)=0\Rightarrow x=0;9\)

2) \(x\left(x-4\right)-x^2=7\Rightarrow-4x=7\Rightarrow x=-\dfrac{7}{4}\)

3) \(3x+2\left(x-5\right)=5\Rightarrow5x-10=5\Rightarrow5x=15\Rightarrow x=3\)

4) \(25x^2-1=0\Rightarrow x^2=\dfrac{1}{25}\Rightarrow x=\pm\dfrac{1}{5}\)

5) \(3x\left(x-2\right)-5\left(x-2\right)=0\Rightarrow\left(x-2\right)\left(3x-5\right)=0\Rightarrow x=2;\dfrac{5}{3}\)

6) \(3x\left(x-7\right)+4\left(x-7\right)\Rightarrow\left(3x+4\right)\left(x-7\right)=0\Rightarrow x=-\dfrac{4}{3};7\)

7) \(4x^2-9=0\Rightarrow x^2=\dfrac{9}{4}\Rightarrow x=\pm\dfrac{3}{2}\)

8) \(10x\left(x-4\right)+2x-8=0\Rightarrow2\left(x-4\right)\left(5x+1\right)=0\Rightarrow x=4;-\dfrac{1}{5}\)

9) \(x\left(2x-5\right)-2x^2=0\Rightarrow x\left(2x-5-2x=0\right)\Rightarrow x=0\)

10) \(2x^2-4x=0\Rightarrow2x\left(x-2\right)=0\Rightarrow x=0;2\)

11) \(2x\left(3-4x\right)+3\left(4x-3\right)=0\Rightarrow2x\left(4x-3\right)-3\left(4x-3\right)=0\Rightarrow\left(4x-3\right)\left(2x-3\right)=0\Rightarrow x=\dfrac{3}{4};\dfrac{3}{2}\)

12) \(2x\left(x-5\right)-2x^2=3\Rightarrow-10x=3\Rightarrow x=-\dfrac{3}{10}\)

dap an:

x=1

1, \(4x-10=0\\ \Leftrightarrow x=\dfrac{5}{2}\)

vậy tập no S=\(\left\{\dfrac{5}{2}\right\}\)

2, \(2x^3+6x^2=x^2+3x\\ \Leftrightarrow2x^2\left(x+3\right)-x\left(x+3\right)=0\\ \Leftrightarrow x\left(2x-1\right)\left(x+3\right)=0\)

\(\Leftrightarrow\) \(x=0\) hoặc \(2x-1=0\) hoặc \(x+3=0\)

\(\Leftrightarrow\) \(x=0\) hoặc \(x=\dfrac{1}{2}\) hoặc \(x=-3\)

vậy tập no S=\(\left\{0,\dfrac{1}{2},-3\right\}\)

3, \(x-5=3-x\\ \Leftrightarrow2x=8\\ \Leftrightarrow x=4\)

vậy tập no S=\(\left\{4\right\}\)

4,\(\left(-10x+5\right)\left(2x-8\right)=0\)

\(\Leftrightarrow\) \(-10x+5=0\) hoặc \(2x-8=0\)

\(\Leftrightarrow\) \(x=\dfrac{1}{2}\) hoặc \(x=4\)

vậy tập no S=\(\left\{\dfrac{1}{2},4\right\}\)

6B, 7A, 8D

Ta có: |17x-5| - |10x+4|=0

<=> |17x - 5| = |10x + 4| 

<=> 17x - 5 = 10x + 4

=> 17x - 10x = 4 + 5

=> 7x = 9

=> x = \(\frac{9}{7}\)

Xét 3 TH:

                                     Vậy x = 9/7 , x = 1/27 

=> |17x - 5 | = | 10x +4 | 

Ta có : \(\left|a\right|=\left|b\right|\Rightarrow\orbr{\begin{cases}a=b\\a=-b\end{cases}}\)

=> 17x -5 = 10x +4 hoặc  17x -5 = - ( 10x + 4 ) 

xét 17x - 5 = 10x +4 

 => x = 9/7 

xét    17x -5 = - ( 10x + 4 ) 

=> x = 1/27

Vậy x = 9/7 hoặc x = 1/27 

a) \(\left(x-5.4\right)=0\)

\(\Leftrightarrow x-20=0\)

\(\Leftrightarrow x=0+20\)

\(\Leftrightarrow x=20\)

b) \(6x+4x=201\)

\(\Leftrightarrow10x=201\)

\(\Leftrightarrow x=201:10\)

\(\Leftrightarrow x=20,1\)

c) \(\left(x-4\right)\left(x-3\right)=0\)

\(\Leftrightarrow\orbr{\begin{cases}x-4=0\\x-3=0\end{cases}}\)

\(\Leftrightarrow\orbr{\begin{cases}x=0+4\\x=0+3\end{cases}}\)

\(\Leftrightarrow\orbr{\begin{cases}x=4\\x=3\end{cases}}\)

a/x bang 0                                               c/x bang 0                  

         cau b hinh nhu sai de roi

mk viet nham

a/x=20

c/ x=4 hoac 3

\(\text{ a, 5-(10x)=-7}\)

\(\Rightarrow\)    10x=5-(-7)

\(\Rightarrow\)    10x=12

\(\Rightarrow\)        x=12:10

\(\Rightarrow\)        x=1,2

    b, (x-5).(2x+8)=0

\(\Rightarrow\) x-5=0        hoặc     2x+8=0

\(\Rightarrow\) x   =0+5       \(\Rightarrow\) 2x    =0+8

\(\Rightarrow\) x   =5           \(\Rightarrow\) 2x     =8

                              \(\Rightarrow\)    x     =8:2

                              \(\Rightarrow\)    x     =4

vậy x\(\in\){5;4}

      c, 2x-9=-8+9

\(\Rightarrow\) 2x-9=1

\(\Rightarrow\) 2x    =1+9

\(\Rightarrow\) 2x    =10

\(\Rightarrow\)   x    =10:2

\(\Rightarrow\)   x     =5

     d, |x-9|.(-8)=-16

\(\Rightarrow\)|x-9|    =-16:(-8)

\(\Rightarrow\)|x-9|    =2

\(\Rightarrow\)  x-9     =\(\hept{\begin{cases}2\\-2\end{cases}}\)

  trường hợp 1:   x-9=2 

                \(\Rightarrow\)  x   =2+9

                \(\Rightarrow\)  x    =11

trường hợp 2:  x-9=-2

            \(\Rightarrow\)   x   =-2+9

           \(\Rightarrow\)    x    =7

vậy x \(\in\){11;7}

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