Write an equation of the line that is perpendicular to the line y = 0.5x+8 that passes through the point (4,6)

First line: 

If you want another line perpendicular to this one, the product of the slopes must be equal to -1.

For the first line: a = 0.5
Then for the perpendicular one, it shloud be a = -2

-2×0.5 = -1

We have then two lines:



Sorry if my english is not quite good..