Is this a polygon?

Yes or no

What signals you that factoring by grouping is the best method to use when factoring a problem?

At the beginning of 1974/75,2 years a man invested #2000 in a bank at 12.5% compound interest, if it degree #650 at the end of each two years to pay his son's school fees, after payment of interest to pay his son's school fees, how much did he have left at the beginning of the 1978/79 school year?

Percent increase and decrease. original number: 45 new number: 18