Juan also has a gym membership. Juan paid $21 for 4 visits and $41 for 9 visits. what is the y-intercept and the slope?

3cm and 6 and 9 cm that a possibility of that question

If you need an equation, it would be y=2x+8, y would be how long it grew, x being weeks.if you need how long he was asleep, it would be 4 weeks if he started with no beard, the equation would be x=8÷2if he did have a beard before hand, the equation would be 2w+x=8

Where is the rest of the question