Answer:
slope of perpendicular line =

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 line with equation
4x + 5y = 35 ( subtract 4x from both sides )
5y = - 4x + 35 ( divide through by 5 )
y = -
x + 7 ← in slope- intercept form
with slope m = -

given a line with slope m then the slope of a line perpendicular to it is
= -
= -
=
