can someone please help me with this question befor 9:20

The question requires you to perform addition and subtraction the polynomial given;
[tex](-10x^2+9)\text{ +}(8x^2-5x\text{ +7})[/tex][tex]-10x^2+8x^2-5x+9+7^{}^{}[/tex]after collecting the like terms, solve as;
[tex]-2x^2\text{ -5x + 16}[/tex]