The slope of the line on the graph is -1/3. Perpendicular lines have slopes which are negative reciprocals of each other. This makes the slope of the new line 3.
Substitute the values m=3 and the point (3,4) into point slope form and simplify.
I wasn't sure how to order things, so I decided to write directly on top of your screenshots. Have a look at the three attachments. Two of which are correct. There is one incorrect answer though you're fairly close.
