To identify the slope of given line you need to rewrite it in the slope-intercept form y = mx + b where m is a slope and b is a y-intercept of the line.
To do that move x to the right side then divide each term of equation by 3.
You will get y = -1/3x + 7/3
From this form of linear equation we can see that the slope for this line is -1/3.
The slopes of perpendicular lines are opposite reciprocals (opposite sign, flipped fraction).
So, the slope of perpendicular line is equal to 3.
Given point (0, 1) is a y-intercept because x-coordinate is equal to 0.
So m=3 and b=1.
Therefore the equation of the perpendicular line will be y = 3x + 1.