We have a line y = 1/3x -6
We want a line that is perpendicular to this line
Perpendicular lines have slopes that multiply to -1
1/3 * m = -1
3 * 1/3 *m = -1 * 3
m = -3
The slope of the perpendicular line is -3
y = mx+b where m is the slope and b is the y intercept
y = -3x+b
We have a point on the line ( 7 ,-23)
Substitute this point into the equation
-23 = -3(7)+b
-23 = -21+b
Add 21 to each side
-23+21 = -21+21+b
-2 = b
y = -3x-2
In slope intercept form, the line perpendicular passing through (7,-23) is
y = -3x-2
