i was never good at math

I need some help with this:
Melanie took her son and three of his friends to the rec. center to swim (two of which are spending the night). Two of the boys got kicked out so everyone needed to be picked up (4.5 hours early). Melanie is at home and in addition to the four boys, she is listening to music from the kitchen computer, a guitar being played at a decent level on the amp and Guitar Hero 2. If a=a glass of ice and b=a can of Classic Coke, find x to the following equation:
a+b+x=ahh, much better
update: To make it worse, two boys are singing Journey (out of the blue because it's not like it's playing in my house). Eric tells them, "Dude, Def Leppard sucks." Now the two break into a soulful sing-along..."pour some sugar on me..." (yeah, I hope you know the rest because I'm stopping there!)