Bài 1:
\(a,\Leftrightarrow-4m-2-1=1\Leftrightarrow m=-1\\ b,\Leftrightarrow2m+1< 0\Leftrightarrow m< -\dfrac{1}{2}\)
\(c,\) PT giao Ox: \(y=0\Leftrightarrow x=-\dfrac{5}{2}\Leftrightarrow A\left(-\dfrac{5}{2};0\right)\Leftrightarrow OA=\dfrac{5}{2}\)
PT giao Oy: \(x=0\Leftrightarrow y=5\Leftrightarrow B\left(0;5\right)\Leftrightarrow OB=5\)
Vì 2>0 nên góc tạo vs Ox là góc nhọn, gọi góc đó là \(\alpha\)
\(\tan\alpha=\dfrac{OB}{OA}=2\approx64^0\\ \Rightarrow\alpha\approx64^0\)