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Câu hỏi: Tìm các số thực $x,y$ thỏa mãn $2x-1+(1-2y)i=2-x+(3y+2)i$.
A. $x=3;y=-\dfrac{1}{5}$
B. $x=1;y=-\dfrac{1}{5}$
C. $x=3;y=\dfrac{3}{5}$
D. $x=1;y=\dfrac{3}{5}$
A. $x=3;y=-\dfrac{1}{5}$
B. $x=1;y=-\dfrac{1}{5}$
C. $x=3;y=\dfrac{3}{5}$
D. $x=1;y=\dfrac{3}{5}$
Ta có:
$\begin{aligned}
& 2x-1+(1-2y)i=2-x+(3y+2)i\Leftrightarrow 3x-3+(-1-5y)i=0 \\
& \Leftrightarrow \left\{ \begin{aligned}
& 3x-3=0 \\
& -1-5y=0 \\
\end{aligned} \right.\Leftrightarrow \left\{ \begin{aligned}
& x=1 \\
& y=-\dfrac{1}{5} \\
\end{aligned} \right. \\
\end{aligned}$
$\begin{aligned}
& 2x-1+(1-2y)i=2-x+(3y+2)i\Leftrightarrow 3x-3+(-1-5y)i=0 \\
& \Leftrightarrow \left\{ \begin{aligned}
& 3x-3=0 \\
& -1-5y=0 \\
\end{aligned} \right.\Leftrightarrow \left\{ \begin{aligned}
& x=1 \\
& y=-\dfrac{1}{5} \\
\end{aligned} \right. \\
\end{aligned}$
Đáp án B.