An equal number of students from two Algebra 1 classes

On an airplane there are two seats on the left side and three seats on the right side there are 90 seats o the right side of the plane

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

Samantha is growing a garden in her back yard. she spend $90 setting up the garden bed and buying the proper garden supplies. in addition, each seed she plants cost $0.25. a. write the function f(x) that represents samantha's total cost on her garden. b. explain what x represents. c. explain what f(x) represents. d. if samantha plants 55 seeds, how much did she spend in total?