I am just starting to learn algebra. My question is -2n-(9-10n)=?

Question

I have to simplify this.
I think it is 8n-9
Can you please tell me if this is correct or how to do it?
Thanks a lot

Answer 1

First of all remove the brackets

-2n-(9-10n)= -2n-9+10n

then group like terms together

-2n-9+10n = 10n-2n-9
thus

10n-2n-9 = 8n-9

So yes, I agree.

Answer 2

the answer is 8n-9