In the distance formula for square root of (x • 2 - x • 1)² + ( y • 2 - y • 1)² How would I tell what numbers go where? for example, (4, -9) and (5, 6)?

the points are (x1,y1) and (x2,y2)

surely your text had examples of this application.
Try plotting the points. You can draw a right triangle with the line between the points as the hypotenuse.

@Oobleck

Thank you so much! :)

To apply the distance formula, you need two sets of coordinates: (x1, y1) and (x2, y2).

In your example, you have two points, (4, -9) and (5, 6). Let's assign the first set of coordinates to (x1, y1) and the second set to (x2, y2).

Therefore,
x1 = 4
y1 = -9

And,
x2 = 5
y2 = 6

Substituting these values into the distance formula, we get:
√[(x2 - x1)² + (y2 - y1)²]

Substituting the x and y values:
√[(5 - 4)² + (6 - (-9))²]

Now, simplify the expression inside the square root:
√[(1)² + (15)²]

Finally, compute the square root to find the distance between the two points:
√(1 + 225)
√226

So, the distance between the points (4, -9) and (5, 6) is approximately √226.