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From: quantgal <email@example.com> To: Teacher2Teacher Public Discussion Date: 2009062910:59:55 Subject: Re: mathematics Assuming your question is sincere, here is a response: Because you are taking the opposite of the absolute value of the product two times. The first time (minus times plus) you multiply a negative times the absolute value product , you will yield a negative answer. The second negative makes that product positive, when you take the opposite the second time. Example: -2 x -3 = (-1 X 2) x (-1 x 3) rearrange: (2 x 3) x (-1) x (-1) 2 x 3 = +6 Substitute and multiply by the first negative: (+6) x (-1) = -6 Substitute and multiply by the second negative: (-6) x (-1) = the opposite of negative 6, which is +6. Therefore, minus times minus is plus.
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