\(2x\left(-2x+1\right)-2x^2=2\\ \Leftrightarrow-4x^2+2x-2x^2=2\\ \Leftrightarrow-6x^2+2x-2=0\\ \Leftrightarrow x\in\varnothing\left(-6x^2+2x-2=-6\left(x^2-2\cdot\dfrac{1}{6}x+\dfrac{1}{36}+\dfrac{11}{36}\right)=-6\left(x-\dfrac{1}{6}\right)^2-\dfrac{11}{6}< 0\right)\)

\(a.x=-0,6\)

\(c.x=-11,6\)

Pt nhju ak!!!

\(-4x^2+20-16x+4x^2=-3\)

\(\left(-4x^2+4x^2\right)-16x=-3-20\)

\(0-16x=-23\)

\(x=\frac{23}{16}\)

CHÚC BN HX TỐT :))

\(-4x\left(x-5\right)-2x\left(8-2x\right)=-3\)

\(\Leftrightarrow-4x^2+20x-16x+4x^2=-3\)

\(\Leftrightarrow4x=-3\Leftrightarrow x=-\frac{3}{4}\)

-4x(x-5)-2x(8-2x)=-3

có:-4x^2+20x-4x^2-16x=-3

     (-4x^2+4x^2)+(20x-16x)=-3

                                        4x=-3

suy ra:x=-3/4

Thanks

-4x(x-5)-2x(8-2x)=-3

-4x^2+20x-16x+4x^2=-3

4x=-3

x=-3/4

<=>(-4)x(x-5)-2x(8-2x)=4x

=>4x=-3

=>x=\(-\frac{3}{4}\)

-4x(x-5)-2x(8-2x)=-3

=>-4x-(-20)-16-4x=-3

=>-4x+20-4x=-3+16

=>-4x-4x=13-20

=>-8x=-7

=>x=(-7):(-8)

=>x=0,875

-4x(x-5)-2x(8-2x)=-3

-4x²+20x-16x+4x²=-3

4x=-3

x=\(\frac{-3}{4}\)

-4x(x-5)-2x(8-2x)=3

-4x²-(-4)x5-2x(8-2x)=3

-4x²+20x-2x(8-2x)=3

-4x²+20x-2x8+2x2x=3

-4x²+20x-16x+4x²=3

(-4x²+4x²)+(20x-16x)=3

4x=3

x=3:4

x=3/4

ý, ghi nhầm -3 thành 3 rồi, kết 

kết quả đúng là -3/4