Constant of proportionality is the constant value of the two proportional quantities, in this problem p and s, where 4 is the factor of proportionality because it is constant or k.
In simple terms, p is in direct proportion to s wherein the increase or decrease in value of s results to the increase or decrease in value of p with 4 the only factor remaining unchanged.
In the above problem, the number 4 is derived from the word square. We all know that a square has 4 sides of equal lengths, therefore, the perimeter is equivalent to the product of 4 and its lenght.
Answer:
I recommend trying this it is real tutors that explain to you on how to do it it's free
Notice that for this question, they are providing you with:
1) The slope of the line (4)
2) a point on the plane through which the line goes (6, -2)
So you can directly use for this the "point-slope" form of a line which is as follows:

This includes m as the slope, and the pair (x0, y0) as the pair representing the point the line goes through.
So, let's use the info they gave you to complete this:

which we can work out a little more:

And even a little more to finish the equation of the line in its standard slope-intercept form:

So the equation of the line is: