Given:
A line passing through (9,-9) and perpendicular to x - 9y - 5 = 0
Asked: What is the equation of the line passing through (9,9)?
Solution:
Step 1: We should arrange the given equation into the form of the slope-intercept form, y = mx +b.
x - 9y - 5 = 0
-9y = -x + 5 (divide both sides by -9 to get y)
y = -x/9 + 5/9
m = -1/9
Step 2: We should get the slope of the line asked through the slope of the given equation above.
m_perpendicular = -1/m
m_perpendicular = -1/(-1/9)
m_perpendicular = 9
Step 3: We will substitute the slope to the formula.
y = 9x + b
In finding b, substitute (9,-9).
-9 = (9*9) + b
b = -90
ANSWER: y = 9x -90
