SOLUTION: Hi everyone, Can someone help me multiply the following problem? (a^2+2ab-b^2)(a^2-7ab+b^2)

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Question 84583: Hi everyone, Can someone help me multiply the following problem?
(a^2+2ab-b^2)(a^2-7ab+b^2)

Found 3 solutions by vertciel, checkley75, rapaljer:
Answer by vertciel(183) About Me  (Show Source):
You can put this solution on YOUR website!
(a^2 + 2ab - b^2)(a^2 - 7ab + b^2)
= a^4 - 7a^3b + a^2b^2 + 2a^3b - 14a^2b^2 + 2ab^3 - a^2b^2 + 7ab^3 - b^4
I'll pass it onto you now.

Answer by checkley75(3666) About Me  (Show Source):
You can put this solution on YOUR website!
A^2+2AB-B^2
A^2-7AB+B^2
--------------------
A^4+2A^3B-A^2B^2-7A^3B-14A^2B^2+7AB^3+A^2B^2+2AB^3-B^4 NOW COMBINE LIKE TERMS.
A^4-5A^3B+9AB^3-B^4.

Answer by rapaljer(4671) About Me  (Show Source):
You can put this solution on YOUR website!
When I solved your problem, I did NOT get the same answer as the one posted by Checkley75. Here is what I got:

%28a%5E2%2B2ab-b%5E2%29%28a%5E2-7ab%2Bb%5E2%29
Multiply the first a%5E2 times everything in the second parentheses:
a%5E2%2A%28a%5E2-7ab%2Bb%5E2%29=a%5E4-7a%5E3b%2Ba%5E2b%5E2

Next, multiply 2ab times everything in the second parentheses:
2ab%2A%28a%5E2-7ab%2Bb%5E2%29=+2a%5E3b+-14a%5E2b%5E2%2B2ab%5E3

Last, multiply -b%5E2 times everything in the second parentheses:
-b%5E2%2A%28a%5E2-7ab%2Bb%5E2%29=+-a%5E2b%5E2+%2B+7ab%5E3+-b%5E4

Now, combine like terms:
a%5E4-7a%5E3b+%2B+a%5E2b%5E2
==> +2a%5E3b+-14a%5E2b%5E2%2B2ab%5E3
=======> -a%5E2b%5E2+%2B+7ab%5E3+-b%5E4
__________________________________________
a%5E4+-5a%5E3b+-14a%5E2b%5E2+%2B+9ab%5E3+-b%5E4+

R^2 at SCC