If you want to multiply two integers, remember these two simple rules.
- if the signs of the two integers are the same, the product is positive
- if the signs of the two integers are different, the product is negative
Examples with the SAME sign:
\(\left( { + 3} \right)\left( { + 9} \right) = 27\)
\(\left( { - 5} \right)\left( { - 6} \right) = 30\)
Examples with DIFFERENT signs:
\(\left( { + 2} \right)\left( { - 5} \right) = - 10\)
\(\left( { - 6} \right)\left( { + 7} \right) = - 42\)