Bernies monthly phone plan can be reprented by the expresion $ 0.10x + $20 where x represents the number if minutes use. If he talked for 300 minutes lat month, how much was his phone bill

How do i do this? i don’t understand

Your friend uses c=50p to find the total cost, c, for the people, p, entering a local amusement park is the cost of admission proportional to the amount of people entering the amusement park? explain.

Will give a: 122 b: 90 c: 48 d: 180