Answer:
d = 6.4
Step-by-step explanation:
As we move from the point (6, 4) to (1, 8), we see x decreasing from 6 to 1, a change of -5, and y increasing from 4 to 8, a change of +4. It may be helpful to plot these two points and to draw a line segment connecting them. We are to find the length of this line segment, which happens to be the hypotenuse of a triangle with base 5 and height 4. Using the Pythagorean Theorem, we get a formula for this distance, d:
d^2 = 5^2 + 4^2 = 25 + 16 = 41
The distance in question is d = √41, or d = 6.4 (to the nearest tenth).