The equations that do not represent linear functions are:
A. 12=2x²+4y²:
This is not a linear function because it includes squared terms (x² and y²). Linear functions can only have variables to the first power.
D. x=9−3/y: This is not a linear function because it includes a term with y in the denominator. Linear functions cannot have variables in the denominator.
The rest of the equations (B, C, E, F) are linear functions because they only involve variables to the first power and do not have variables in the denominator.