Step-by-step explanation:
y = 3x - 6
the slope of a line is always the factor of x in the equation. in our case here : 3 = 3/1.
the slope is the y/x ratio indicating how many units y changes, when x changes by a certain amount of units (e.g. when going from one point on the line to another).
the perpendicular slope (crosses the original line in a right angle = 90 degrees) turns x and y upside-down and flips the sign.
so, in our case, it is -1/3.
the equation for the perpendicular line looks like this then :
y = (-1/3)×x + b
to get b we use the provided point and it's x and y values.
6 = (-1/3)×-3 + b = 1 + b
b = 5
so, the full equation of the perpendicular line is
y = (-1/3)×x + 5