Question

Select linear or nonlinear to correctly classify each function

Answer 1

y = 3x^2 + 7 is nonlinear.  The other 3 functions are linear.

Answer 2

Linear functions are

`y=2x-9\\y=-10.2\\3x+5y=15`

The only non-linear function is

`y=3x^(2) +7`

Basically, a linear function is defined by those which curve is a line. Or their polynomial expression is first grade, that is, the major exponent of variables is one, which is not the case with the third function, that's why is not linear.