Bài 5:
Tọa độ giao điểm là:
\(\left\{{}\begin{matrix}-4x+3=x+1\\y=x+1\end{matrix}\right.\Leftrightarrow\left\{{}\begin{matrix}x=\dfrac{2}{5}\\y=\dfrac{7}{5}\end{matrix}\right.\)
Bài 4:
\(\Leftrightarrow2\left(\dfrac{1}{2}-3x\right)-3\left(\dfrac{9}{2}+2x\right)=42-2\left(\dfrac{1}{2}-4x\right)-6x\)
\(\Leftrightarrow2-6x-\dfrac{27}{2}-6x=42-1+8x-6x\)
\(\Leftrightarrow-12x-\dfrac{23}{2}=2x+41\)
=>-14x=105/2
hay x=-15/4