Explanation:
the general slope intercept form is
y = ax + b
a is the slope. a parallel line must have the same slope.
in our case here it is -3.
b is the y-intercept (the point, where the line crosses the y-axis, meaning the y value when x=0).
we get b by using the point coordinates in the equation and solve for b :
-4 = -3×-9 + b = 36 + b
b = -40
so, the full equation of the parallel line is
y = -3x - 40