Читать книгу Algebra I All-in-One For Dummies - Mary Jane Sterling, Mary Sterling Jane - Страница 54
Dividing Signed Numbers
ОглавлениеThe rules for assigning the sign of the answer when dividing signed numbers are exactly the same as those for multiplying signed numbers (see “Multiplying Signed Numbers” earlier in this chapter.) The rules do differ, though, because you have to divide, not multiply.
When you divide signed numbers, just count the number of negative signs in the problem — in the numerator, in the denominator, and perhaps in front of the problem. If you have an even number of negative signs, the answer is positive. If you have an odd number of negative signs, the answer is negative.
Q.
A. There are two negative signs in the problem, which is even, so the answer is positive. The answer is +4.
Q.
A. There are three negative signs in the problem, which is odd, so the answer is negative. The answer is –9.
Q.
A. There are two negative signs — one of them in front of the fraction — so the answer is positive. The answer is +11.
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