Sapling Week 1 #9

[Jaclyn Schwartz 1I]

For question 9, I cant get the right answer no matter how hard I try. Here is the problem and my values?

At equilibrium, the concentrations in this system were found to be [N2]=[O2]=0.100 M and [NO]=0.600 M.
N2(g)+O2(g)↽−−⇀2NO(g)
If more NO is added, bringing its concentration to 0.900 M, what will the final concentration of NO be after equilibrium is re‑established?

My K=36
[NO]^2/[O2][N2]=k
ice
N2(g)+O2(g)↽−−⇀2NO(g)
i 0.1 0.1 +0.9
c +x +x -2x
e 0.1+x 0.1+x 0.9-2x
[0.9-2x]^2/[0.1+x]^2 =36
x=0.0375
0.9-2x=[NO]

What am I doing wrong? Anything would be extremely helpful!

[Jaclyn Schwartz 1I]

I figured my error out! thanks tho!

[Brandon Gruender 3F]

Im honestly struggling to see any faults in your work. Was your final answer 0.825 M? If it was I do not know, maybe contact your TA to help.

[Natalie Do 3F]

Thank you for outlining your steps thoroughly! I also got stuck on this question and this helped a lot.