a:
b: Tọa độ A là:
\(\left\{{}\begin{matrix}y=0\\\dfrac{2}{3}x+2=0\end{matrix}\right.\Leftrightarrow\left\{{}\begin{matrix}y=0\\\dfrac{2}{3}x=-2\end{matrix}\right.\)
=>\(\left\{{}\begin{matrix}y=0\\x=-2:\dfrac{2}{3}=-2\cdot\dfrac{3}{2}=-3\end{matrix}\right.\)
Tọa độ B là:
\(\left\{{}\begin{matrix}y=0\\2x+2=0\end{matrix}\right.\Leftrightarrow\left\{{}\begin{matrix}y=0\\2x=-2\end{matrix}\right.\)
=>\(\left\{{}\begin{matrix}x=-1\\y=0\end{matrix}\right.\)
Tọa độ C là:
\(\left\{{}\begin{matrix}\dfrac{2}{3}x+2=2x+2\\y=2x+2\end{matrix}\right.\Leftrightarrow\left\{{}\begin{matrix}-\dfrac{4}{3}x=0\\y=2x+2\end{matrix}\right.\)
=>\(\left\{{}\begin{matrix}x=0\\y=2\cdot0+2=2\end{matrix}\right.\)
Vậy: A(-3;0); B(-1;0); C(0;2)
