Question

On a map of downtown, 12th street is perpendicular to Avenue J. The equation y=-4x+3 represents 12th street. What is the equation representing Avenue J if it passes through the point (8,16)?

Answer 1

slope of 12th street = -4
so slope of Ave J = 1/4

so now you have m and a point
new equation:
y = (1/4)x + b
but (8,16) lies on it
16 = (1/4)(8) + b
16 = 2 + b
b = 14

y = (1/4)x + 14

In my class the question would have been worded this way:

Find the equation of the perpendicular to y = -4x +3, which passes through (8,16)