Answer:
6x^2 + 4x + 17
Step-by-step explanation:>
To add the expressions (x^2+11x+9) and (5x^2-7x+8), we simply combine like terms.
First, we add the coefficients of the terms with the same degree of x:
x^2 + 5x^2 = 6x^2
Next, we add the coefficients of the terms with x:
11x - 7x = 4x
Finally, we add the constant terms:
9 + 8 = 17
Putting it all together, the sum of the expressions is:
6x^2 + 4x + 17