\(\left(\frac{2}{3}+x\right)\left(\frac{1}{5}-2x\right)=0\)

\(\Leftrightarrow\orbr{\begin{cases}\frac{2}{3}+x=0\\\frac{1}{5}-2x=0\end{cases}\Leftrightarrow\orbr{\begin{cases}x=-\frac{2}{3}\\-2x=-\frac{1}{5}\end{cases}\Leftrightarrow}}\orbr{\begin{cases}x=-\frac{2}{3}\\x=\frac{1}{10}\end{cases}}\)

Vậy:.......

#H

\(\left(\frac{2}{3}+x\right)\left(\frac{1}{5}-2x\right)=0\)

\(\Rightarrow\frac{2}{3}+x=0\)hoặc\(\frac{1}{5}-2x=0\)

\(\Rightarrow x=-\frac{2}{3}\)   hoặc\(2x=\frac{1}{5}\)

\(\Rightarrow x=-\frac{2}{3}\)   hoặc\(x=\frac{1}{10}\)

Xin lỗi bạn mình k làm đầy đủ đc ạ :

2) a) Vì (x-3)(2y+1) = 7

=> x-3 và 2y + 1 \(\in\)Ư(7) = { 1;7}

Ta có bảng :

Vậy...

b) (2x+1)(3y-2) = -55

=> 2x +1 và 3y - 2 \(\in\)Ư(-55) = { 1; 5 ; 11 ; 55}

Ta có bảng :

Sr kẻ bảng thừa cột :))

Vậy...

1.a) x = 0

   b) x = 1 , y = 2

   c) x = 9

2.x = 6

mik ko bik có đúng ko nhưng dù sao cx chúc b học tốt nhé ^^ 

bn ơi cho mik xin cách làm đi

a) \(xy+2x+y+11=0\)

\(\Leftrightarrow x\left(y+2\right)+\left(y+2\right)+9=0\)

\(\Leftrightarrow\left(x+1\right)\left(y+2\right)=0-9\)

\(\Leftrightarrow\left(x+1\right)\left(y+2\right)=-9\)\(=-1.9=-3.3=-9.1\)

\(\Rightarrow\left[{}\begin{matrix}x+1=-1;y+2=9\\x+1=-3;y+2=3\\x+1=-9;y+2=1\end{matrix}\right.\)

\(\Rightarrow\left[{}\begin{matrix}x=-2;y=7\\x=-4;y=1\\x=-10;y=-1\end{matrix}\right.\)

Vậy:.............

a) \(\frac{-5}{9}+\frac{5}{9}:\left(1\frac{2}{3}-2\frac{1}{12}\right)\)

\(=\frac{-5}{9}+\frac{5}{9}:\left(\frac{5}{3}-\frac{25}{12}\right)\)

\(=\frac{-5}{9}+\frac{5}{9}:\frac{\left(-5\right)}{12}\)

\(=\frac{-5}{9}+\frac{5}{9}.\frac{12}{\left(-5\right)}\)

\(=\frac{-5}{9}.\left(1+\frac{12}{5}\right)\)

\(=\frac{-5}{9}.\frac{17}{5}\)

\(=\frac{-17}{9}\)

b) \(\frac{-7}{25}.\frac{11}{13}+\frac{-7}{25}.\frac{2}{13}-\frac{18}{25}\)

\(=\frac{-7}{25}.\left(\frac{11}{13}+\frac{2}{13}\right)-\frac{18}{25}\)

\(=\frac{-7}{25}-\frac{18}{25}\)

\(=-1\)

Chúc bn học tốt !!!

ổi câu a sao mk bấm mấy ra kq là 5/9

\(\left(3x-1\right)\left(\frac{-1}{2}x+5\right)=0\)

\(\orbr{\begin{cases}3x-1=0\\\frac{-1}{2}x+5=0\end{cases}}\)

\(\orbr{\begin{cases}x=\frac{1}{3}\\x=10\end{cases}}\)

\(\frac{1}{4}+\frac{1}{3}:(2x-1)=-5\)

\(\Rightarrow\frac{1}{3}:(2x-1)=-5-\frac{1}{4}\)

\(\Rightarrow\frac{1}{3}:(2x-1)=\frac{-21}{4}\)

\(\Rightarrow2x-1=\frac{1}{3}:-\frac{21}{4}\)

\(\Rightarrow2x-1=\frac{1}{3}\cdot-\frac{4}{21}\)

\(\Rightarrow2x-1=\frac{-4}{63}\)

\(\Rightarrow2x=-\frac{4}{63}+1\)

\(\Rightarrow2x=\frac{59}{63}\Leftrightarrow x=\frac{59}{126}\)

\(\left(x+\frac{1}{2}\right)\cdot\left(\frac{2}{3}-2x\right)=0\)

TH1 : \(\Rightarrow x+\frac{1}{2}=0\)

\(x=0-\frac{1}{2}\)

\(x=\frac{-1}{2}\)

TH2 : \(\Rightarrow\frac{2}{3}-2x=0\)

\(2x=0+\frac{2}{3}=\frac{2}{3}\)

\(x=\frac{2}{3}\div2=\frac{1}{3}\)

\(\Rightarrow x=\frac{-1}{2};\frac{1}{3}\)

\(\left(x+\frac{1}{5}\right)^2+\frac{17}{25}=\frac{26}{25}\)

\(\left(x+\frac{1}{5}\right)^2=\frac{26}{25}-\frac{17}{25}\)

\(\left(x+\frac{1}{5}\right)^2=\frac{9}{25}=\left(\frac{3}{5}\right)^2\)

\(x=\frac{3}{5}^2-\frac{1}{5}^2\)

\(x=\frac{2}{5}\)

1/4 : x=(-2)-3/4

1/4 : x=-11/4

x=1/4 :( -11/4)

x=-1/11

(x-10) . 11 = 22 

x - 10       = 22 : 11

x - 10     = 2

=> x = 12

b, 2x + 15 = (-27)

 2x           = (-27)- 15 

2x          =   - 42

=> x =  -21

c , tự làm

a) ( x - 10 ) . 11 = 22               

      x - 10 = 22 : 11

      x - 10 = 2

             x = 2 + 10

             x = 12

Vậy x = 12       

b) 2x + 15 = - 27

    2x = - 27 - 15

    2x = - 42

      x = - 42 : 2

      x = - 21

Vậy x=-21                       

c) - 765 - ( 305 + x ) = 100   

                  305 + x = - 765 - 100

                  305 + x = - 865

                            x = - 865 - 305

                            x = - 1170

Vậy x=-1170                    

d)2^x:4=16

   2^x:2²=2⁴

    2^x-2=2⁴

=> x-2=4

         x=4+2

         x=6

Vậy x=6

f) ( 17x - 25 ) : 8 + 65 = 9²

   ( 17x - 25 ) : 8 + 65 = 81

   ( 17x - 25 ) : 8 = 81 - 65

   ( 17x - 25 ) : 8 = 16

      17x - 25 = 16 . 8

      17x - 25 = 128

      17x = 128 + 25

       17x = 153

           x = 153 : 17

           x = 9

Vậy x=9