Answer:
4x +5y = -20
Step-by-step explanation:
Starting with an equation in standard form, you can write the equation for the perpendicular line by swapping the x- and y-coefficients and negating one of them. You want the x-coefficient to be positive, so it is convenient to negate that one here. This gives you the equation ...
4x +5y = (some constant)
You find the value of the constant by evaluating the expression at the given point:
4x +5y = 4(5) +5(-8) = -20
The desired equation is ...
4x +5y = -20
