Answer:
two or zero positive real roots, one or zero negative real roots
Explanation:
f(x) = 9x³ − 2x² − x + 5
There are 2 sign changes, so the number of positive real zeros is 2 or an even number less than that. So there are two or zero positive real roots.
f(-x) = 9(-x)³ − 2(-x)² − (-x) + 5
f(-x) = -9x³ − 2x² + x + 5
There is 1 sign change, so the number of negative real zeros is 1 or an even number less than that. So there is exactly 1 negative real root.
Your answer is correct.