Determine the sum of the polynomials below.
(-12a^2+11a+9)+(6a^2-5a-6)=
To find the sum of these polynomials, we need to combine like terms.
(-12a^2+11a+9)+(6a^2-5a-6)
To combine like terms, add the coefficients for each corresponding term.
(-12a^2 + 6a^2) + (11a - 5a) + (9 - 6)
Simplifying further:
-6a^2 + 6a + 3