Answer:
[tex]\large \boxed{\sf \ \ x^2 + 7x + 5 \ \ }[/tex]
Step-by-step explanation:
[tex]\mathrm{\sf (-3x^2 + 2x -4) + (4x^2 + 5x + 9)}[/tex]
Remove brackets.
[tex]\large{\sf -3x^2 + 2x -4 + 4x^2 + 5x + 9}[/tex]
Group like terms.
[tex]\large{\sf -3x^2 + 4x^2 + 2x + 5x + 9 -4}[/tex]
Combine like terms.
[tex]\large{\sf x^2 + 7x + 5}[/tex]
