Review of Introductory Mathematics SIGNED NUMBERSMultiplicationMultiplication of signed numbers may be performed by using the following rules:The product of any two numbers with like signs is positive:(+)(+) = (+) or (–)(–) = (+).The product of any two numbers with unlike signs is negative:(+)(–) = (–) or (–)(+) = (–).The product is negative if there is an odd number of negatives.The product is positive if there is an even number of negatives.Example:(+3)(+3) = +9(–2) (+4) = –8(–1) (–2) (+1) (–2) = –4(–2) (+2) (+2) (–2) = +16Zero times any number equals zero.Multiplying by –1 is the equivalent of changing the sign.DivisionDivision of signed numbers may be performed using the following rules:Rule 1: The quotient of any two numbers with like signs is positive:(+)/(+) = (+) or (–)/(–) = (+)Rule 2: The quotient of any two numbers with unlike signs is negative:(+)/(–) = (–) or (–)/(+) = (–)Rule 3: Zero divided by any number not equal to zero is zero.Rev. 0 Page 51 MA-01

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