Hi candygirl04,

has a slope of 2. Did you know that?

The slope of any line perpendicular to that line will have a slope that is the negative reciprocal of 2. In other words invert and change its sign.

Thus the perpendicular would have a slope of

You didn't say which form of the linear equation to use, so I'll use the point slope form with our new slope and point (4, 2).

That's it!