1) This is the equation for distance between two points:

Don't make it fool you, this is just a fancy translation of

or the Pythogarean theorem.
The first parentheses or the x ones represents the difference between their location horizontally. Which is also a "leg".
The second or the y ones stands for the vertical difference.
Distance is the hypotenuse of those two values.
When we plug in the givens into the equation:

Simplify:



2) The template for a "directly proportional" equation is:

where k is the constant which causes the "proportional" change.
The only one we see in the choices which is in this format is A.
3) To find x or y-intercepts, we need to plug in 0 for the other value.
For example, x-intercept of this equation is:

Simplify:




So, the x-intercept is (-6, 0).
For y-intercept, the equation becomes:

The zero cancels the six:

When we divide both sides by -4:

The y-intercept is (0, 9).