$$-x^2+ 9x -16 .$$
Work Step by Step
We simplify by removing the parentheses and then add the like terms as follows: $$ (2x^2 + 5x - 9) - (3x^2 - 4x + 7)\\ =2x^2 + 5x - 9 - 3x^2 + 4x - 7\\ =-x^2+ 9x -16 .$$
You can help us out by revising, improving and updating this answer.Update this answer
After you claim an answer you’ll have 24 hours to send in a draft. An editor will review the submission and either publish your submission or provide feedback.