SOLUTION: 8.) a^2 - b^2-c^2-2bc / a^2 + b^2-c^2-2ab please explain this to me... i tried factoring by grouping and ended up with a completely wrong answer on my worksheet ):

Algebra ->  Polynomials-and-rational-expressions -> SOLUTION: 8.) a^2 - b^2-c^2-2bc / a^2 + b^2-c^2-2ab please explain this to me... i tried factoring by grouping and ended up with a completely wrong answer on my worksheet ):       Log On


   

Question 127928: 8.) a^2 - b^2-c^2-2bc / a^2 + b^2-c^2-2ab
please explain this to me...
i tried factoring by grouping and ended up with a completely wrong answer on my worksheet ):
Answer by oscargut(2103) About Me  (Show Source):
You can put this solution on YOUR website!
you have to use these formulas:
(p^2-q^2)=(p-q)(p+q)
(p+q)^2=P^2+2pq+q^2
(p-q)^2=P^2-2pq+q^2
a^2 - b^2-c^2-2bc / a^2 + b^2-c^2-2ab
= a^2-(b+c)^2/(a-b)^2-c^2
= [a-(b+c)][a+(b+c)]/[(a-b)-c][(a-b)+c]
=(a-b-c)(a+b+c)/(a-b-c)(a-b+c)
=(a+b+c)/(a-b+c)