Question

Is the line x – 3y = 4 perpendicular to the line 3x – y = 7?

Answer 1

x − 3y = 4

3y = x − 4

`y = 1/3x - 4/3`

Slope of this line = `1/3`

3x − y = 7

y = 3x − 7

Slope of this line = 3

Product of slopes of the two lines = 1 ≠ −1

So, the lines are not perpendicular to each other.