[tex]k:\ y=m_1x+b_1\\l:\ y=m_2x+b_2\\\\l\ \perp\ k\ \iff\ m_1m_2=-1\to m_2=-\dfrac{1}{m_1}[/tex]
[tex]90)\\-y+2=-x\ \ |-2\\-y=-x-2\ \ |\text{change the signs}\\y=x+2\to m_2=1\\Answer:\ m=-\dfrac{1}{1}=-1\\\\91)\\-2=-y\to y=2\to\text{horizontal line}\\Answer:\ Unde fined\ slope\\\\92)\\y=1\to\text{horizontal line}\\Answer:\ Unde fined\ slope\\\\93)\\x=2+y\ \ \ |-2\\y=x-2\to m_2=1\\Answer:\ m=-\dfrac{1}{1}=-1\\\\94)\\0=3+x\ \ \ |-3\\x=-3\to\text{vertical line}\\Answer:\ m=0[/tex]
