What is the explicit formula for this sequence?
-7, -4,-1, 2,
a. a^n=-7+(n-)
b. a^n=-7+(n-1)3
c. a^n=8+n(n-1)3
d. a^n=3+(n-)

Ineed i don’t get this at all! and you

What is the percent of increase for a population that changed from 438,000 to 561,000

Dylan and dusty plan to take weekly surfing lessons together. if the 2-hour lessons are $20 per person and they plan to spend $100 each on new surfboards, what is the maximum number of lessons the two can take if the total amount spent for lessons and surfboards is at most $480?