C+d^2=36 is this linear or nonlinear?

Medium sodas cost $1.25 and hot dogs cost $2.50. natalie’s group brought in pizzas but is buying the drinks at concession stand. how many medium sodas can natalie’s group buy with $20? make a table to show answer.

Each of the walls of a room with square dimensions has been built with two pieces of sheetrock, a smaller one and a larger one. the length of all the smaller ones is the same and is stored in the variable small. similarly, the length of all the larger ones is the same and is stored in the variable large. write a single expression whose value is the total area of this room. do not use any method invocations.

Can someone me with this? i’m not sure what to put for my equations.