Pls help i need help pls pls pls only got 5 min

Which expressions are equivalent to -6 + 3m

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?

Two variables, x and y, vary inversely, and x=12 when y=4. what is the value of y when x=3?