\(a,PT\Leftrightarrow3x^2+3x-2x^2-4x=-1-x\Leftrightarrow x^2=-1\left(\text{vô nghiệm}\right)\)

Vậy: ...

\(b,PT\Leftrightarrow4x\left(x-2019\right)-\left(x-2019\right)=0\Leftrightarrow\left(x-2019\right)\left(4x-1\right)=0\Leftrightarrow\left[{}\begin{matrix}x=2019\\x=\dfrac{1}{4}\end{matrix}\right.\)

Vậy: ...

\(c,PT\Leftrightarrow\left(x-4-6\right)\left(x-4+6\right)=0\Leftrightarrow\left(x-10\right)\left(x+2\right)=0\Leftrightarrow\left[{}\begin{matrix}x=10\\x=-2\end{matrix}\right.\)

Vậy: ...

\(d,PT\Leftrightarrow\left(x+4\right)^2=0\Leftrightarrow x=-4\)

Vậy: ...

\(e,PT\Leftrightarrow x\left(x+6\right)-7\left(x+6\right)=0\Leftrightarrow\left(x+6\right)\left(x-7\right)=0\Leftrightarrow\left[{}\begin{matrix}x=-6\\x=7\end{matrix}\right.\)

Vậy: ...

\(f,PT\Leftrightarrow\left(5x-3\right)\left(5x+3\right)=0\Leftrightarrow x=\pm\dfrac{3}{5}\)

Vậy: ...

   + -2X-12+6X-60=8

<=>4X=80]

<=> X = 20

         V.....

   + -8X-36 +8X -3 - X - 13 =0

 <=> -X = 52

 <=> X = -52

           V.....

   + 14X +7\(X^2\)-7\(X^2\)-21X=14

    <=> -7X  =14

     <=> X= -2 

              V .......

1: Ta có: \(x^2+7x+6=0\)

\(\Leftrightarrow\left(x+1\right)\left(x+6\right)=0\)

\(\Leftrightarrow\left[{}\begin{matrix}x=-1\\x=-6\end{matrix}\right.\)

2: Ta có: \(x^2+7x+12=0\)

\(\Leftrightarrow\left(x+3\right)\left(x+4\right)=0\)

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

3: Ta có: \(x^2+8x+15=0\)

\(\Leftrightarrow\left(x+3\right)\left(x+5\right)=0\)

\(\Leftrightarrow\left[{}\begin{matrix}x=-3\\x=-5\end{matrix}\right.\)

4: Ta có: \(x^2+5x+4=0\)

\(\Leftrightarrow\left(x+1\right)\left(x+4\right)=0\)

\(\Leftrightarrow\left[{}\begin{matrix}x=-1\\x=-4\end{matrix}\right.\)

đây mà là toán lớp 1 á bọn chị họ lớp 3 mà còn chưa học đây này

\(x^3-7x+6=0\)

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

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

\(\Leftrightarrow\left(x+3\right)\left[x\left(x-2\right)-1\left(x-2\right)\right]=0\)

\(\Leftrightarrow\left(x+3\right)\left(x-2\right)\left(x-1\right)=0\Leftrightarrow\left[{}\begin{matrix}x=-3\\x=2\\x=1\end{matrix}\right.\)

x³ hả cậu

<=>\(\left(x+3\right)\left(x-2\right)\left(x-1\right)=0\)

<=>\(\left[{}\begin{matrix}x+3=0\\x-2=0\\x-1=0\end{matrix}\right.< =>\left[{}\begin{matrix}x=-3\\x=2\\x=1\end{matrix}\right.\)

a, =>-2x+12+6x-60=8

=>4x+48=8

=>4x=56

=>x=14

b,=>-8x-36-8x-3-x-13=0

=>-17x-52=0

=>-17x=52

=>x=-52/17

c,=>14x+7x^2-7x^2-21x=14

=>-7x=14

=>x=-2

a <=> -2x+12 +6x-60-8=0

<=>4x-56=0

<=>x=56/4=14

Vậy S=(4)

ban oi la toan lop 6!!!!!!!!!!!!!!

\(x^6-7x^3-8=0\)

\(x^6-7x^3\)     \(=0+8\)

\(x^6-7x^3\)     \(=8\)

\(x^6-7x^3\)      \(=2^3\)

\(x^6-7x\)        \(=2\)

     mk làm đến đây thui nha chỗ sau bn tự làm nha@@

x⁶-7x³-8=0 

x⁶-7x^{3  = 0+8}

x⁶- 7x³= 8 =2³

x^6-7   ⁼2 suy ra x =2³

x⁶        = 2³+7 

x⁶     = 15

suy ra x= 15⁶