Answer
Answer C
Work Step by Step
Given: $f(x)=2x^4-5x^3+10x^2-9$
The leading coefficient is $\pm 1,\pm 2$
The constant term is $\pm 1,\pm3,\pm 9$
The possible rational zeros are: $\pm \frac{1}{1},\pm \frac{1}{2},\pm \frac{3}{1},\pm \frac{3}{2},\pm \frac{9}{1},\pm \frac{9}{2},\pm 1,\pm \frac{1}{2},\pm 3,\pm \frac{3}{2},\pm 9,\pm\frac{9}{2},...$
We can notice that $\frac{5}{2}$ cannot be a possible zero of $f$.
Hence, the answer is C.
