MULTIPLYING INTEGERS LESSON 2-4, P. 83

RULES When multiplying integers with like (the same) signs, the product (answer) will be positive. EX.) negative x negative = positive positive x positive = positive 5 * 3 = ____ (-5) * (-3) = ____ When multiplying integers with different signs, the product (answer) will be negative. EX.) negative x positive = negative positive x negative = negative (-5) * 3 = ____ 5 * (-3) = _____ 2

PRACTICE 3

MULTIPLYING WITH MORE THAN TWO FACTORS When multiplying more than two factors, count the number of negative integers: *If you have an odd number of negative integers, then your product (answer) will also be negative. *If you have an even number of negative integers, then your product (answer) will be negative. TRY THESE: Negative Positive Positive Negative 4

MULTIPLYING WITH VARIABLES Sometimes you will be asked to simplify. Sometimes you will be asked to evaluate. When asked to simplify, you will not be able to solve the problem out to a numerical answer. Your answer will have a variable in it. Multiply your coefficients first; then combine your variables EXAMPLE: 3a * (-5b) = -15ab When asked to evaluate, you need to substitute each variable for the values given and solve based on the rules for multiplying integers. Be careful to substitute what is given for each value. EXAMPLE: x = -4, y = 3 -xy = 12 - (-4) * 3 4 * 3 = 12 5