Step-by-step explanation:
the slope of a line function is always the factor of x.
in our case : -1/4
it is the ratio y/x indicating how many units y changes, when x changes a certain amount of units.
in our case y decreases by 1 for every x increase by 4.
now, the perpendicular slope simply changes x and y upside-down and flips the sign.
in our case it is : 4/1 = 4
so, the line function in point slope form is then (using the new slope and the point coordinates)
y - 3 = 4(x - 1)