What is an equation of the line that passes through the point (1,5) (1,5) and is perpendicular to the line x+3y=15x+3y=15?

Answer 1

y = mx + b

The slope of the given line is -1/3. The slope of a perpendicular line is

m = -1/(-1/3) = 3

y = 3x + b

Now use the given point (1,5) to find b and finish from here.