1. find the value of y so that the line passing through (6, y) and (7, 5) has a slope of -3.

2. write the equation of a line in point-slope form that has a slope of -1 and passes through the point (-2, 5).

3.write the equation of a line in slope-intercept form passing through (2, 7) and (-2, 9) y=1/3x+5 and passes through (-9, 5)

5. write the equation of a line in slope intercept form that is perpendicular to the line y = –4x and passes through the point (2, 6)

6. write the equation of a line in slope-intercept form that has a slope of and passes through the point (8, -1)

I believe for some of these you're looking for the equation:
y-y1=m(x-x1)
m being slope
(x1 , y1) being the point

So, using question two for an example,
You will leave x and y as they are and plug in the values you know for m, x1, and y1. 5 for y1 because it is the y value, and -2 for x1 under the same reasoning.
y-5 = -1 (x - (-2)) 
y-5 = -1 (x + 2) Solve for parentheses first by distributing the -1
y-5 = -x -2 Add 5 to each side to change its side.
y = -x -2 +5 simplify like numbers by adding 5 and -2
y = -x + 3 This will be your answer for number two

If you give me a moment I'll solve the rest, if you want explanations I can give them as well.