I think its -1 i not very smart so it probably wrong
He used the property of addition. Hope this helps. Please mark me as brainliest if I am right.
Perpendicular lines have slopes that are inverse reciprocals of each other. That would give you the new slope in your equation. After that plug (6,2) into point slope form and solve to get your final equation.
Answer:
20
Step-by-step explanation: