Help please and tysm to whoever does :))

Aboat costs 19200 and decreases in value by 12% per year. how much will it cost in 5 years

The fence around a quadrilateral-shaped pasture is 3a^2+15a+9 long. three sides of the fence have the following lengths: 5a, 10a-2, a^2-7. what is the length of the fourth side of the fence?

Write each of the following numerals in base 10. for base twelve, t and e represent the face values ten and eleven, respectively. 114 base 5 89t base 12