Is the distance between the points (–3, 4) and (–7, 4)?

a.
0

b.
3

c.
4

d.
10

By the Pythagorean Theorem:

c^2=a^2+b^2

And then some refer to this as the distance formula...

d^2=x^2+y^2

And when you are dealing with two points...

d^2=(dx)^2+(dy)^2

In this case:

d^2=(-7--3)+(4-4)^2

d^2=(-4)^2+0^2

d^2=16

d=4

So the distance between the two point is 4 units.

(We could have just noticed that the y coordinates were the same and said the distance was just -3--7=4 :P, but the way I worked it is how you will almost always have to.)