Final answer:
The function y = 10 + 5x - 3x² is nonlinear because it has a highest power of x equal to 2.
Step-by-step explanation:
The function y = 10 + 5x - 3x² is nonlinear.
This can be determined by examining the highest power of x in the function. In this case, the highest power of x is 2. A function is considered linear if the highest power of x is 1, and nonlinear if the highest power is 2 or greater.
Therefore, since the function y = 10 + 5x - 3x² has a highest power of x equal to 2, it is a nonlinear function.