Cheyenne, these are the answers to these questions:
• Positive + Positive : then m+n is positive ,always
,
• Negative + Negative: then m+n is negative ,always
,
• Positive + Negative: then m+n is negative ,sometimes
,
• Positive * Positive : then m * n is positive, always
,
• Negative * Negative: then m * n is negative ,never
Cheyenne, this is really important you keep in mind:
"Two like signs make a positive sign,
two unlike signs make a negative sign"