a)\(x^2+2y^2+2xy-2y+1=0\)

\(\Leftrightarrow x^2+2xy+y^2+y^2-2y+1=0\)

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

\(\Leftrightarrow\hept{\begin{cases}y-1=0\\x+y=0\end{cases}}\Leftrightarrow\hept{\begin{cases}y=1\\x=-y=-1\end{cases}}\)

Vậy x=-1 y=1

a)  \(x^2+2y^2+2xy-2y+1=0\)

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

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

\(\Rightarrow\orbr{\begin{cases}\left(x+y\right)^2=0\\\left(y-1\right)^2=0\end{cases}}\Leftrightarrow\orbr{\begin{cases}x+y=0\\y-1=0\end{cases}\Leftrightarrow\orbr{\begin{cases}x=-y\\y=1\end{cases}\Rightarrow}x=-1;y=1}\)

b) \(5x^2+3y^2+z^2-4x+6xy+4z+6=0\)

\(\Leftrightarrow\left(2x^2-4x+2\right)+\left(3x^2+6xy+3y^2\right)+\left(z^2+4z+4\right)=0\)

\(\Leftrightarrow2.\left(x-1\right)^2+3.\left(x+y\right)^2+\left(z+2\right)^2=0\)

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

           \(\left(x+y\right)^2=0\Rightarrow x+y=0\Rightarrow y=-x=-1\) 

            \(\left(z+2\right)^2=0\Rightarrow z+2=0\Rightarrow z=-2\)

3x^2-5x+2=0

<=>3x²-3x-2x+2=0

<=>3x.(x-1)-2.(x-1)=0

<=>(x-1)(3x-2)=0

<=>x-1=0 hoặc 3x-2=0

<=>x=1 hoặc 3x=2

<=>x=1 hoặc x=2/3

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

<=>  \(\left(x-3\right)\left(5x-1\right)=0\)

<=>  \(\orbr{\begin{cases}x-3=0\\5x-1=0\end{cases}}\)

<=>  \(\orbr{\begin{cases}x=3\\x=\frac{1}{5}\end{cases}}\)

Vay..........

Đăng từng câu đio

,(8x-3).(3x+2)-(4x+7).(x+4)=(2x+1).(5x-1)-33 đúng không bạn

a,Để \(|2x+1|+|x-2|=0\Leftrightarrow\hept{\begin{cases}2x+1=0\\x-2=0\end{cases}}\)(vô lý)

=> ko có x thỏa mãn

b,\(|x+5|=2x-1\Leftrightarrow1-2x< x+5< 2x-1\)

giai gium mik cau c 

...... mk ko bít làm

\(16-5x^2-3=0\)

\(\Leftrightarrow16-5x^2=0+3\)

\(\Leftrightarrow16-5x^2=3\)

\(\Leftrightarrow5x^2=16-3\)

\(\Leftrightarrow5x^2=13\)

\(\Leftrightarrow x^2=\frac{13}{5}\)

\(\Leftrightarrow x^2=2,6\)

\(\Leftrightarrow1,61\approx1,6\)

 \(\Rightarrow x=1,6\)

\(16-5x^2-3=0\)

\(\Leftrightarrow16-5x^2=3\)

\(\Leftrightarrow5x^2=16-3\)

\(\Leftrightarrow5x^2=13\Leftrightarrow x^2=\frac{13}{5}\)

\(\Rightarrow\orbr{\begin{cases}x=\sqrt{\frac{13}{5}}\\x=-\sqrt{\frac{13}{5}}\end{cases}}\Leftrightarrow\orbr{\begin{cases}x=\frac{\sqrt{65}}{5}\\x=-\frac{\sqrt{65}}{5}\end{cases}}\)

\(16-5x^2-3=0\)

\(5x^2=16-3\)

\(5x^2=13\)

\(x^2=13:5\)

\(x^2=\frac{13}{5}\)

\(x=\sqrt{\frac{13}{5}}\)

\(x=\frac{\sqrt{65}}{5}\approx1,6\)