Answer:
See Explanation
Step-by-step explanation:
Missing in the question is the slope of line r.
We'll assume that the slope (m) of line r is
[tex]m = -\frac{1}{3}[/tex]
When two lines are perpendicular, their slope are related in:
[tex]m_2 = -1/m_1[/tex]
[tex]m_2 = -1/\frac{-1}{3}[/tex]
[tex]m_2 = -1 * -3[/tex]
[tex]m_2 = 3[/tex]
The equation of the (3,-6) is:
[tex]y - y_1 = m(x - x_1)[/tex]
Where
[tex](x_1,y_1) = (3,-6)[/tex]
So:
[tex]y - (-6) = 3(x - 3)[/tex]
[tex]y +6 = 3x - 9[/tex]
Make y the subject
[tex]y = 3x - 9 - 6[/tex]
[tex]y = 3x - 15[/tex]
Please note that this answer might be incorrect to you based on the assumed value. However, the step will guide you in solving similar questions