Question 153471
factor completely: 
9m^2-9 
choices:
1) (3m-3)+(3m+3)
2) (3m+3)^2
3) (3m+3)(3m-3)
4) (3m-3)^6 
??what is the difference between option 1 and option 3?
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Since these are your choices, 1 and 3 are both correct
and there is no difference.
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A better way to factor your problem is:
= 9(m^2-1)
=9(m-1)(m+1)
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Cheers,
Stan H.