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multiply -7 (2a square minus 4) how do i work the problem? Answered

im doing basic concepts in algebra and i need to how to solve this pronlem

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lemonie (author)2010-02-19

To do as Kiteman advised you, this is your answer:
-7(2a2-4)
is
-14a2+28

L

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steveastrouk (author)lemonie2010-02-20

Its a style thing, but I don't like hanging minus signs, so I always write
28-14a2

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lemonie (author)steveastrouk2010-02-20

I'd prefer that too, but I was doing a "literal" there.

L

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kelseymh (author)2010-02-18

Orksecurity has it almost right.  The =word you need to know is associativity.  Here's a hint:  a × (b + c) = a×b + a×c. 

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orksecurity (author)kelseymh2010-02-19

Thanks for the correction.

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Kiteman (author)2010-02-19

For this specific example, multiply each thing inside the brackets by each thing outside the brackets.

Beware of your signs.

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orksecurity (author)2010-02-18

Transitivity and commutivity.  Think about how you might do it if a was a specific number but you weren't allowed to subtract 4 before doing the multiplication.

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