Whats the answer to 4x+8y=40 when y =0.8

How do i do this? i don’t understand

Two students were asked if they liked to read. is this a good example of a statistical question? why or why not? a yes, this is a good statistical question because a variety of answers are given. b yes, this is a good statistical question because there are not a variety of answers that could be given. c no, this is not a good statistical question because there are not a variety of answers that could be given. no, this is not a good statistical question because there are a variety of answers that could be given

The cost of using a service is $0.25 per min. what equation correctly represents the total cost c, in dollars, for d days of use?