SOLUTION: Factor completely. b^2 – ab – 6a^2 I got this answer this time is it right? (b – 6a)(b + a)

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Question 79035: Factor completely.
b^2 – ab – 6a^2
I got this answer this time is it right?
(b – 6a)(b + a)
Answer by stanbon(75887) About Me  (Show Source):
You can put this solution on YOUR website!
b^2 – ab – 6a^2
You are looking at the 1st and 3rd terms and forgetting about the middle term.
Think of two numbers whose product is -6 and whose sum is -1.
The numbers are -3 and +2
Replace the middle term, -ab, with -3ab+2ab
b^2-3ab+2ab-6a^2
Factor the 1st two and the last two terms separately
b(b-3a)+2a(b-3a)
Factor again to get:
(b-3a)(b+2a)
Check this by multiply it out.
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Cheers,
Stan H.