Final answer:
Function 1 is nonlinear, while Functions 2, 3, and 4 are linear.
Step-by-step explanation:
The functions can be classified as linear or nonlinear based on their equations.
1. 72 = x3 + y: This is a nonlinear function because it includes variables raised to a power other than 1.
2. y + 1 = 5(x - 9): This is a linear function because it can be written in the form y = mx + b, where m and b are constants.
3. 7y + 2x = 12: This is a linear function because it can also be written in the form y = mx + b.
4. 4y = 24: This is a linear function because it can be written in the form y = mx + b.