Re: plz plz plz help me
A short-circuit means all the current will flow through it and none through the rest of the circuit connected between the same two points as the short. So the current no longer branches; it simply flows entirely through the short.
Note that the short-circuit connects together the ends of both R* and R**. Therefore, the line shorts out both R* and R** so it does not matter what value they are. They are now replaced by zero ohms.
I find it strange, though, that the whole circuit seems to be actually short-circuited between points a and b. If that is truly the case, then you can do anything you want to the other resistors, short them or disconnect them, the resistance between a and b is still zero.