simplify 5x^2+2-9x-8x^2

To simplify the expression 5x^2 + 2 - 9x - 8x^2, combine like terms by adding the coefficients of similar terms:

(5x^2 - 8x^2) + (-9x) + 2

Simplifying the first two terms:

(-3x^2) + (-9x) + 2

Thus, the simplified expression is -3x^2 - 9x + 2.