Pleaseee Help Meee question number 7 Pls

[10 points, algebra 2]according to my answer key the restrictions are -1 and 4. but why not positive 1?

The graph shows the charges for a health club in a month. make a function table for the input-output values. writes an equation that can be used to find the total charge y for the number of x classes

If you can solve all of these i will give ! - 4% of 190 - 4% of 162.5 - 4% of 140 - a 4% increase from 155.1 - a 4% increase from 159.8