Find the equations of sides of a triangle

[kate]

1. The middles of a triangle are L(-1;2), M(3;-1) and N(0;4). Find the equations of its sides.
Answer:5x + 3y - 1 =0; 3x + 4y - 16 = 0 and 2x - y - 7 = 0.


2. Find the equation of the circumference which touches the X axis at the beginning and passes through point A(0;-4).


3. Find the equations of the medians of the triangle with points A(6;7), B(2;11) and C(-3;13).
Answer:11x + 7y - 58 = 0; 38x + 13y - 137 = 0; 16x - y - 21 = 0.


4. Find the equation of the circumference which touches the Y axis in point A(0;-3) and has radius 2.[/i]

[Guest]

The first problem
I get the following equations of triangle sides:

5x + 3y - 3 = 0; 3x + 4y - 16 = 0 and 2x - y - 7 = 0