I NEED DESPERATE HELP WITH COORDINATE GEOMETRY! PLEASE HELP!?

I am having a really hard time getting this Geometry lesson done. I more or less have half-way correct answers or wrong answers. I just need help figuring them out. Please help me with all of them and not just do one or two. All of these questions are questions on specific questions on my lesson. This just isn't the whole lesson or anything. It's questions I am having trouble figuring out. Thank you!

1. Indicate in standard form the equation of the line passing through the given points.

A(4, 1), B(5, 2)

The answer I got: x-3=y

2. Indicate in standard form the equation of the line passing through the given points.

R(3, 3), S(-6, -6)

The answer I got: y= -x-3

3. Indicate in standard form the equation of the line passing through the given points.

B(0, 0), C(4, -4)

The answer I got: x-y=4

4.Indicate in standard form the equation of the line passing through the given point and having the given slope.

B(6, 2), m = -1/2

The answer I got:x+y= -4

5. Indicate in standard form the equation of the line passing through the given point and having the given slope.

D(5, -2) m = 2/5

The answer I got: x+3y= -4

6.Indicate the equation of the given line in standard form.

The line through (2, -1) and parallel to a line with slope of 3/4.

The answer I got: 5x+2y= -11

7. Indicate the equation of the given line in standard form.

The line with slope 9/7 and containing the midpoint of the segment whose endpoints are (2, -3) and (-6, 5).

The answer I got: 2x+5y=7

8.Indicate the equation of the given line in standard form.

The line through the midpoint of and perpendicular to the segment joining points (1, 0) and (5, -2).

The answer I got: 2x-7=y

9. Indicate the equation of the given line in standard form.

The line containing the midpoints of the legs of right triangle ABC where A(-5, 5), B(1, 1), and C(3, 4) are the vertices.

The answer I got: x+8y=0

^^Note: These answers above are answers I got somewhat right. I would really appreciate if you could work them out and point out what I did wrong. Thank you! The ones below are ones I got completely wrong and I can't figure them out.

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1. Indicate the equation of the given line in standard form.

The line containing the longer diagonal of a quadrilateral whose vertices are A (2, 2), B(-2, -2), C(1, -1), and D(6, 4).

2.Indicate the equation of the given line in standard form.

The line containing the median of the trapezoid whose vertices are R(-1, 5) , S(1, 8), T(7, -2), and U(2,0).

3. Indicate the equation of the given line in standard form.

The line containing the altitude to the hypotenuse of a right triangle whose vertices are P(-1, 1), Q(3, 5), and R(5, -5).

4. Indicate the equation of the given line in standard form.

The line containing the diagonal of a square whose vertices are A(-3, 3), B(3, 3), C(3, -3), and D(-3, -3). Find two equations, one for each diagonal.

**Note: ^^These are questions that completely and absolutely stump me. I can not figure them out! Please most definitely help me with these!!

Note: Just a reminder, this isn't homework. This is a lesson I am trying to complete and have been for the past 2 hours. I really need to finish this lesson today! Just a reminder, I really beg that you don't do just five and then say "good luck with the rest" because I am having trouble with these specific questions. If you can work them all out and then explain how you did it, that would be great and I would appreciate it a lot. The last 4 are the ones that truly stump me the most, so if you're going to pick questions, at least help me out with those last 4. Thank you so much again for answering!