a) \(x\left(x-6\right)=0\)

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

\(\Rightarrow\left[{}\begin{matrix}x=0\\x=6\end{matrix}\right.\)

b) \(\left(-7-x\right)\left(-x+5\right)=0\)

\(\Rightarrow\left[{}\begin{matrix}-7-x=0\\-x+5=0\end{matrix}\right.\)

\(\Rightarrow\left[{}\begin{matrix}x=-7\\x=-5\end{matrix}\right.\)

c) \(\left(x+3\right)\left(x-7\right)=0\)

\(\Rightarrow\left[{}\begin{matrix}x+3=0\\x-7=0\end{matrix}\right.\)

\(\Rightarrow\left[{}\begin{matrix}x=-3\\x=7\end{matrix}\right.\)

d) \(\left(x-3\right)\left(x^2+12\right)=0\)

\(\Rightarrow\left[{}\begin{matrix}x-3=0\\x^2+12=0\end{matrix}\right.\)

\(\Rightarrow\left[{}\begin{matrix}x=3\\x^2=-12\text{(vô lý)}\end{matrix}\right.\)

\(\Rightarrow x=3\)

e) \(\left(x+1\right)\left(2-x\right)\ge0\)

\(\Rightarrow\left[{}\begin{matrix}\left[{}\begin{matrix}x+1\ge0\\2-x\ge0\end{matrix}\right.\\\left[{}\begin{matrix}x+1\le0\\2-x\le0\end{matrix}\right.\end{matrix}\right.\)

\(\Rightarrow\left[{}\begin{matrix}\left[{}\begin{matrix}x\ge-1\\x\le2\end{matrix}\right.\\\left[{}\begin{matrix}x\le-1\\x\ge2\end{matrix}\right.\end{matrix}\right.\)

\(\Rightarrow\left[{}\begin{matrix}-1\le x\le2\\x\in\varnothing\end{matrix}\right.\)

\(\Rightarrow-1\le x\le2\)

f) \(\left(x-3\right)\left(x-5\right)\le0\)

\(\Rightarrow\left[{}\begin{matrix}\left[{}\begin{matrix}x-3\le0\\x-5\ge0\end{matrix}\right.\\\left[{}\begin{matrix}x-3\ge0\\x-5\le0\end{matrix}\right.\end{matrix}\right.\)

\(\Rightarrow\left[{}\begin{matrix}\left[{}\begin{matrix}x\le3\\x\ge5\end{matrix}\right.\\\left[{}\begin{matrix}x\ge3\\x\le5\end{matrix}\right.\end{matrix}\right.\)

\(\Rightarrow3\le x\le5\)

a) =>\(\left[{}\begin{matrix}x=0\\x-6=0\end{matrix}\right.=>\left[{}\begin{matrix}x=0\\x=6\end{matrix}\right.\)

b => \(\left[{}\begin{matrix}-7-x=0\\-x+5=0\end{matrix}\right.\Rightarrow\left[{}\begin{matrix}x=-7\\x=5\end{matrix}\right.\)

d) => \(\left[{}\begin{matrix}x-3=0\\x^2+12=0\end{matrix}\right.\Rightarrow\left[{}\begin{matrix}x=3\\x^2=-12\end{matrix}\right.\)(vô lí) => x=3

a) 461 + (x - 45) = 387

              x - 45 = 387 - 461

              x - 45 = -74

                    x = -74 + 45

                    x = -29

b) 2x - 8 = x + 4

    2x - x = 8 + 4

            x = 12

c) 11 - (-53 + x)= 97

           -53 + x = 11 - 97

            -53 + x = -86

                    x = -86 - (-53)

                    x = -33

d) 2.|x - 5| - 16 = 0

    2.|x - 5| = 0 + 16

     2.|x - 5| = 16

        x - 5 = 16 : 2

         x - 5 = 8

               x = 8 + 5

                x = 13

e) |x| - 8 = 4

           x = 4 + 8

           x = 12

A 461+(x-45)=387

           X-45 =387-461

           x-45 = -74

               x= -74 + 45

               x =-29

B  2x-8 = x+4

    (2x-x)= 4-(-8)

     x     = 12

C 11-(-53+x) =97

          -53+x =11-97

          -53+x= -86

                 x= -86 - (-53)

                  x=    -33

a) 

\(\left(x+1\right)\left(y-2\right)=5\\ \Rightarrow\left(x+1\right),\left(y-2\right)\inƯ\left(5\right)=\left\{1;-1;5;-5\right\}\)

Ta có bảng:

Vậy \(\left(x;y\right)=\left(0;7\right),\left(-2;-3\right),\left(4;3\right),\left(-6;1\right)\)

b) 

\(\left(x-5\right)\left(y+4\right)=-7\\ \Rightarrow\left(x-5\right),\left(y+4\right)\inƯ\left(-7\right)=\left\{1;-1;7;-7\right\}\)

Ta có bảng:

Vậy \(\left(x;y\right)=\left(6;-11\right),\left(4;3\right),\left(12;-5\right),\left(-2;-3\right)\)

461 + (x - 45) = 387

           x - 45   = 387 - 461

           x - 45   = -74

           x          = -74 + 45

           x          = -29

11 - (-53 + x) = 97

        -53 + x  = 11 - 97

        -53 + x  = -86

                 x  = -86 - -53

                 x  = -33

- (x+84) + 213 = -16

   x - 84 + 213 = -16

   x - 84           = -16 - 213

   x - 84          = -229

   x                 = -229 + 84

   x                 = -145

461 + ( x - 45 ) = 387

            x - 45  = 387 - 461

             x - 45 = - 74

                    x = - 74 + 45

                    x = - 29

Vậy x = - 29

a) 461+(x-45)=387

<=>461+x-45=387

<=>416+x =387

<=>x =387-416

<=>x =-29

b) -12(x-5)+7(x-3) =5

<=>-12x+60+7x-21=5

<=>-5x+39 =5

<=>-5x =5-39

<=>-5x =-34

<=>x =(-34):(-5)=6,8

a) 461+(x – 45) = 387

x-45= 461-387

x-45=74

x= 74+45

x=119

Vậy...

b) 11– (53+ x) = 97

53+x= 11-97

53+x= -86

x= -86-53

x= -139

Vậy....

a) -29

b)33

c) 145

a ) -29

b ) 33

c ) 145

haidangbb chơi 2 nick nha

a,461+(x-45)=387

=>x-45=387-461

=>x-45=-74

=>x=-74+45

x=-29

a, 461 + ( x - 45 ) = 378                        

              ( x - 45 ) = 461 - 378 

              ( x - 45 ) = 83 

                         x = 83 - 45 

                         x = 38