mathematica simplify denominator

Question

In this algebraic expression, how to force Mathematica to calculate first a common

denominator and then to simplify:

(32768 Sqrt[\[Pi]] Va)/((7/b^2 + 2/mua^2)^(3/2) mua^3) +
  (32 Sqrt[\[Pi]] Va)/((b^2 + mua^2)^(3/2) (2/b^2 + 1/(b^2 + mua^2))^(3/2)) 
  + (6144 Sqrt[\[Pi]] Va)/((b^2 + mua^2)^( 3/2) (3/b^2 + 1/(b^2 + mua^2))^(3/2))

the expression is too long, this is only a part.

Answer 1

Use

Together[ (your expression here) ]

Answer 2

For this expression it works with Together[] and then Apart[]. But for a larger expression with 50 terms like these I used Expand[expression]//Factor, and then again Expand[expression] to separate the terms.