SOLUTION: I am working on a problem that I am having difficulty answering. There is not an answer key, so I cannot see where I am going wrong in my calculations. This is not for a test; just

Algebra ->  Polynomials-and-rational-expressions -> SOLUTION: I am working on a problem that I am having difficulty answering. There is not an answer key, so I cannot see where I am going wrong in my calculations. This is not for a test; just      Log On


   



Question 847555: I am working on a problem that I am having difficulty answering. There is not an answer key, so I cannot see where I am going wrong in my calculations. This is not for a test; just homework.
Problem: Completely factor the difference of two squares. (I do not need to solve.)
98-162z^2
What I get is sq. rt. of 2, times (7-9z^2).
I know I need to finish factoring the 9 & the z^2, but I am stuck. Please help? Frustrated because I can see it's so easy but my brain is caught up.
Thanks in advance for your help!

Found 2 solutions by psbhowmick, richwmiller:
Answer by psbhowmick(878) About Me  (Show Source):
Answer by richwmiller(17219) About Me  (Show Source):
You can put this solution on YOUR website!
-2*(9z-7)*(9z+7)
First factor out -2
Why minus ?
To put the z first.
-2*(81z^2-49)
-2*(9z-7)*(9z+7)