Multiplication and Division of Signed Numbers In Beginning Algebra ?

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Raeb22

Open Questions

Multiplication and Division of Signed Numbers In Beginning Algebra ?

I am teaching myself beginning algebra with self-help books. :)

How to work these problems:

(+5)(+3) =+15
(-5)(-7) =+35
Also, How to find the product of more than two numbers:
(+2)(-5)(+3)(-3) =
Do I go by the order of operations?
Thank you for any help.

Posted 226 day ago

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Answers (9)

jdrew39

Always remember that two positives equal a positive, two negatives equal a positive, a negative and a positive equal a negative. The order of operations is P=parenthesis, E=exponents, M=multiplication, D=division, A=addition, and S=subtraction. you have only parenthesis in your questions, you will not need to follow the order of operations. So to begin, you have +3*+5=+15 (2 positives). Your next question.....-5*-7=+35 (two negatives=a positive). In your third example you have +2*-5=-10 (one positive and one negative=negative). Next you have +3*-3=+9 (one positive and one negative=negative). To finish the question you then multiply -9*-10=90 (two negatives=positive). I hope that this has helped you.

Posted 221 day ago

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marycurry

Here are the basic rules for multiplying or dividing signed numbers:

all answers are positive EXCEPT when the numbers are opposite signs (one positive, one negative), then the answer is negative.

As for multiplying a series--they can be multiplied in any order. Just remember to follow the rules of the signs: (-2)(5)(6)(-6) = -10(-36) = 360. OR 30(12) = 360.

Posted 225 day ago

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YummyCookies

ur first two examples are perfect!
For the last example, it doesnt matter if you
dont use order of operation. just in the way they show u!

Posted 226 day ago

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In Algebra, a positive number times another positive number becomes positive. such as:
(+6)x(+ 5) ==> +30
Also negative times negative becomes positive, example:
(-3)x(-8) ==> +24
In your last exampl, (+)(-)(+)(-) ==> (+), because two negatves will give positive result, so
(+2)(-5)(+3)(-3) ==> (+90).
Order of multiplication is not important, for exampl if you multiply -5 and +3 first then the result multiplied by -3, finaly the second result multiplied by +2, you will get the same +90.

Posted 226 day ago

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In Algebra, (+)(+) => (+), i.e. plus times plus becomes plus. And:
(-)(-) => (+), i.e. negative times negative becomes positive. Only (-)(+) becomes negative.
So in your first problem,there are two positive numbers and when multiplied, you get positive answer. In your second example, you have two negative numbers and when multiplied, you get positive result. In your last example, two positive and two negative numbers when multiplied will give positive result of +90.

Posted 226 day ago

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matherapist

When multiplying positive and negative numbers you can multiply them in any order to get the magnitude of the answer. to get the sign of the answer, count the number of negative signs. if it is odd (1,3,5 etc) the magnitude will have a negative sign in front of it. if the number of negative signs is even (2,4 etc) the sign of the magnitude is positive.

The rule of odd and even negative signs also applies to division.

examples
(3)(-4) = -12 1 negative sign
(3)(-2)(5)(-4) = 120 2 negative signs
(3)(-2)(-5)(-4) - -120 3 negative signs

[(3)(-2)]/[2)(-3)(-2)]= -(1/2) since there are 3 negative signs. You could also say (-6)/(12) where you evaluate the numerator and denominator separately

Posted 226 day ago

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asad.taj

When you try to multiply two numbers then there are two things you have to do
first maultiply the signs according to following rule
+ x + = +
+ x - = -
- x + = -
- x - = +
and then after putting the sign do the multiplication of numbers.
example :
+2 x +2 = +4
-2 x +2 = -4
-2 x -2 = 4

Posted 226 day ago

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MFB13

With regards to numbers that have a negative sign, always use the following rules in order to get the correct sign for your solution:
1. For multiplication and division:
i. If there are an even number of negative sign numbers, the final answer will always be a positive sign number.
ii. If there are an odd number of negative sign numbers, the final answer will alwaysbe a negative sign number.

Posted 226 day ago

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Doctor Bob

There are only two orders of operations in this particular case which actually combine as one. You rid the problem of PARENTHESES and at the same time you note that parentheses hugging parentheses is a form of MULTIPLICATON. And so, 2 x -5 x 3 x -3 = 90 The reason that it is a POSITIVE 90 rather than a NEGATIVE 90 is because there is an EVEN number of negatives. It's as if each negative sign hugs another negative sign to give you a positive sign. (If there was an ODD number of negatives signs, the answer would be NEGATIVE because there would still be a NEGATIVE without a partner, so to speak.)
Suggestion, get your hands on CLIFFS QUICK REVIEW OF BASIC MATH AND PRE-ALGEBRA in most book stores. It is excellent for self-teaching. Later there is also a CLIFFS ALGEBRA and a CLIFFS GEOMETRY.
Further questions: RevDrBob@aol.com

Posted 226 day ago

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