SOLUTION: Hi. My brain is being fried by this equation. I have been trying to solve it for three hours. The textbook says the answer is the square root of 20, but I am still unable to work i

Algebra ->  Coordinate-system -> SOLUTION: Hi. My brain is being fried by this equation. I have been trying to solve it for three hours. The textbook says the answer is the square root of 20, but I am still unable to work i      Log On


   

Question 778595: Hi. My brain is being fried by this equation. I have been trying to solve it for three hours. The textbook says the answer is the square root of 20, but I am still unable to work it out. Using the Pythagorean Theorem, calculating the distance between A and B.

A's coordinates are: (Xa: a + 1. Ya: 2a + 3).
B's coordinates are: (Xb: a - 1. Yb: 2a - 1).


The steps to the textbook's answer elude me. Any help would be appreciated.
Answer by psbhowmick(878) About Me  (Show Source):
You can put this solution on YOUR website!
The distance is given be
d+=+sqrt%28%28Xa-Xb%29%5E2%2B%28Ya-Yb%29%5E2%29
d+=+sqrt%28%28%28a%2B1%29-%28a-1%29%29%5E2%2B%28%282a%2B3%29-%282a-1%29%29%5E2%29
d+=+sqrt%282%5E2%2B4%5E2%29
d+=+sqrt%284%2B16%29
d+=+sqrt%2820%29
d+=+2sqrt%285%29