Question

Find the equation of the line x – 7y + 5 = 0 perpendicular to the line and having x-intercept 3.

Answer 1

The equation of the perpendicular line will be 7x + y + k = 0.

Since x-intercept is 3, the line passes through the point (3, 0). So we have;

7(3) + 0 + k = 0 

⇒ 21 + 0 + k = 0 

⇒ k = -21

Therefore the equation is 7x + y – 21 = 0.