Could someone help me

What is the difference between regular convex and concave polygons

Ricky takes out a $31,800 student loan to pay his expenses while he is in college. after graduation, he will begin making payments of $190.66 per month for the next 30 years to pay off the loan. how much more will ricky end up paying for the loan than the original value of $31,800? ricky will end up paying $ more than he borrowed to pay off the loan.

Adele is five years older than timothy. in three years, timothy will be 2/3 of adele’s age. what is adele‘s current age?