Question

Write an equation of the line that is perpendicular to 3x + 9y = 7 and passes through the point (6, 4)

Answer 1

y=3x-14

Explanation:

Answer 2

The perpendicular line will have the x and y coefficients swapped and one of them negated. We can write the desired line as
9(x -6) -3(y -4) = 0
where the coordinates of the point of interest are (6, 4).
Dividing by 3, this is
3(x -6) -(y -4) = 0
3x -y = 14

An equation for the line of interest is ...
3x -y = 14