(2x^2-6x-5)+(-9x^2+5x-4)

To solve the expression (2x^2-6x-5)+(-9x^2+5x-4), we combine like terms.

First, we group the x^2 terms together:
(2x^2 - 9x^2) + (-6x + 5x) + (-5 - 4)

Next, we simplify each group of terms:
(-7x^2) + (-x) + (-9)

Finally, we combine the simplified terms:
-7x^2 - x - 9

Therefore, (2x^2-6x-5)+(-9x^2+5x-4) simplifies to -7x^2 - x - 9.