Answer:
y + 7 = - 3(x - 8)
Explanation:
the equation of a line in slope- intercept form is
y = mx + c ( m is the slope and c the y- intercept )
given the equation
y =
x + 4 ← in slope- intercept form
with slope m =

given a line with slope m then the slope of a line perpendicular to it is
= -
= -
= - 3
the equation of a line in point- slope form is
y - b = m(x - a)
m is the slope and (a, b ) a point on the line
we have nm = - 3 and (a, b ) = P (8, - 7 )
substitute these values into the equation
y - (- 7) = - 3(x - 8) , that is
y + 7 = - 3(x - 8) ← equation of line in point- slope form