Answer:
[tex]\huge\boxed{m=-3}[/tex]
Step-by-step explanation:
The standard form:
[tex]Ax+By=C[/tex]
The slope-intercept form:
[tex]y=mx+b[/tex]
[tex]m[/tex] - slope
[tex]m=-\dfrac{A}{B}\\\\-6x-2y=9\to A=-6;\ B=-2\\\\m=-\dfrac{-6}{-2}=-3[/tex]
[tex]-6x-2y=9[/tex]
convert to the slope intercept form:
[tex]-6x-2y=9\qquad|\txt{add}\ 6x\ \text{to the both sides}\\\\-2y=6x+9\qquad|\text{divide both sides by (-2)}\\\\y=-3x-4.5\to m=-3[/tex]