Find the polar coordinates for each point below.
1. (-1,-√3)
2. (-2,2√3)
3. (-4,0)

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?

Can someone me out here and the tell me the greatest common factor

The? half-life of a radioactive substance is 20 years. if you start with some amount of this? substance, what fraction will remain in 120 ? years