Question

Are the functions linear or nonlinear?

1. y = 2x − 9
2. y = −10.2
3. y = 3x2 + 7
4. 3x + 5y = 15

Answer 1

they are all linear bcz x and y have powers 1 if there had been y^2 or x^2 or 3 it would have been no more linear