Answer:
A. 9y + 3 = 0
Explanation:
To know if a function is linear without graphing it, check if the function is a polynomial of the first degree, because linear functions are polynomials of the first degree. This means that the power of the x-value should be equal to 1.
The only function without this trait is 9y + 3 = 0, so that is our nonlinear function.
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