Respuesta :

if a line's slope is [tex] \frac{a}{b} [/tex], the slope of the perpendicular line is [tex] -\frac{b}{a} [/tex]
in this case, the given line has a slope 4, which is 4/1, so the perpendicular line has a slope/gradient [tex] -\frac{1}{4} [/tex]