Đáp án:
11) \(\left[ \begin{array}{l}
y = \dfrac{3}{2}\\
y = - \dfrac{3}{2}
\end{array} \right. \to \left[ \begin{array}{l}
x = \dfrac{5}{2}\\
x = - \dfrac{5}{2}
\end{array} \right.\)
Giải thích các bước giải:
\(\begin{array}{l}
10)\left\{ \begin{array}{l}
x = \dfrac{3}{4}y\\
\dfrac{3}{4}y.y = 12
\end{array} \right.\\
\to \left\{ \begin{array}{l}
{y^2} = 16\\
x = \dfrac{3}{4}y
\end{array} \right.\\
\to \left[ \begin{array}{l}
y = 4\\
y = - 4
\end{array} \right. \to \left[ \begin{array}{l}
x = 3\\
x = - 3
\end{array} \right.\\
11)\left\{ \begin{array}{l}
x = \dfrac{5}{3}y\\
\dfrac{{25}}{9}{y^2} - {y^2} = 4
\end{array} \right.\\
\to \left\{ \begin{array}{l}
x = \dfrac{5}{3}y\\
{y^2} = \dfrac{9}{4}
\end{array} \right.\\
\to \left[ \begin{array}{l}
y = \dfrac{3}{2}\\
y = - \dfrac{3}{2}
\end{array} \right. \to \left[ \begin{array}{l}
x = \dfrac{5}{2}\\
x = - \dfrac{5}{2}
\end{array} \right.
\end{array}\)
