Multiplication of Integers
2 * 3 means to add 2 to itself 3 times:
2 + 2 + 2 = 6
-3 * 2 means to add -3 to itself 2 times:
-3 + -3 = -6
4 * -2 means to add -2 to itself 4 times: -2 + -2 +
-2 + -2 = -8
-2 * -3 has no meaning except,
possibly, the opposite of 2 * -3,
that is, add -3 to itself 2 times then use the opposite of the result:
-3 + -3 = -6, the inverse of -6 is 6. So, -2 * -3 = 6.
It is probably best to learn and use the rules:
a. 2 same sign integers multiplied yield a
positive product.
b. 2 mixed sign integers
multipled yield a negative product.
But what if you have more than 2 integers
multiplied together?
Example: -2 * 3 * -4
well, simplify by taking 2 factors at a time from left to right:
-2 * 3 is -6, so we have -6 * -4.
Now
-6 * -4 = 24, the answer.
Example: 2 * 5 * -6 * -2 * 3
10 * -6 * -2 * 3
-60 * -2 * 3
120 * 3
360
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This is another FREE ALGEBRA PRINTABLE presented to you from the
Algebra section of
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