Answer:
[tex]-11x^{2}[/tex]
Step-by-step explanation:
since [tex]-x^{2} and -10x^{2}[/tex] have the same terms, then you could simply add their coefficients.
[tex]-x^{2}[/tex] has a coefficient of -1: [tex]-1x^{2}[/tex]
adding to [tex]-10x^{2}[/tex] will give you [tex]-11x^{2}[/tex].
