A line can be expressed in the form y = mx + b where m is the slope and b is the y-intercept. For y = 4x - 7, the slope is 4 and the y-intercept is -7. This line rises 4 units for every increase in x.
It is not possible to say that a line is perpendicular or parallel unless a reference line is provided. If the slope of a line is 0 or infinity, it could be said that the line is horizontal or vertical.
The slope of the line y = 4x - 7 is 4, nothing further can be said.
To answer this question, you must have a second equation. If the equation given is the first equation, then the second equation will have:
"y=4x + some constant " These two lines are parallel.
"y= -1/4 x + some constant" These two lines would be perpendicular.
The slope is the number next to x. Lines with the same slope (or, same number next to x) are parallel.
Lines that are perpendicular have negative reciprocal slopes. hence, 4 and -1/4.
I hope this helps. Best of luck.