Answer:
y=−x/3+7 .
Explanation:
The equation of the line in the slope-intercept form is y=3x−5. 
The slope of the perpendicular line is negative inverse: m=−13. 
So, the equation of the perpendicular line is y=−x3+a. 
To find a, we use the fact that the line should pass through the given point: 5=(−13)⋅(6)+a. 
Thus, a=7.
Therefore, the equation of the line is y=−x/3+7.