In the elementary reaction of NOBr(2) + NO ==> 2 NOBr, is the rate equal to k[NOBr(2)][NO] or k[NO]^2[Br(2)]? My textbook says that the rate is equal to k[NO]^2[Br2] but I don't know why...are these two the same thing?

I tried a few examples, where I tested out some numbers but the two rates yielded different results. Can anyone help me?

Thanks