Question

Find an equation of the line​ l, where l is perpendicular to y=4x and passes through the point ​(1​,4​).

Answer 1

y = 4x + 0   →   m = 4

perpendicular slope = -1/4

Point-Slope formula: y - y₁ = m(x - x₁)  ; where (x₁, y₁) is the given point

y - 4 = (-1/4)(x - 1)

4(y - 4) = -1(x - 1)

4y - 16 = -x + 1

x + 4y - 16 = 1

x + 4y = 17