SOLUTION: Factor completely 7a^2 – 28b^2

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Question 189833: Factor completely
7a^2 – 28b^2
Answer by jim_thompson5910(35256) About Me  (Show Source):
You can put this solution on YOUR website!
7a%5E2-28b%5E2 Start with the given expression


7%28a%5E2-4b%5E2%29 Factor out the GCF 7


7%28a%5E2-%282b%29%5E2%29 Rewrite 4b%5E2 as %282b%29%5E2


7%28a%2B2b%29%28a-2b%29 Factor a%5E2-%282b%29%5E2 to get %28a%2B2b%29%28a-2b%29 (note: use the difference of squares formula)


So 7a%5E2-28b%5E2 completely factors to 7%28a%2B2b%29%28a-2b%29