Re move a number from a vector

This should be an easy one, but I haven't been able to figure it out, 

x<-c(2, 4, 6, 9, 10)
#how do I remove a single value
x<-x[-2] # will remove the second element of the vector not the number 2 

This is part of a loop that looks a little like this...

x<-c(2, 4, 6, 9, 10)
remove.value<-4
#then I need to remove the value returned by the loop.

Thanks,
Josh