# Simplifying tedious expression

I have the following output in Mathematica I'd like to simplify, but using Simplify[] and FullSimplify[] got me nowhere.

1/s^2 266.428 GG^4 (-1. MSR^4 + s (1.69 - 1. t) -
1. (-1.69 + t) (-1.69 + t) + MSR^2 (-3.38 + 21. t)) +
(-8.5683 MSR^8 + s^3 (3.62011 - 2.14208 t) + MSR^6 (74.2122 + 8.5683 s + 24.6339 t) +
s^2 (-71.8863 - 5.43016 t - 5.89071 t^2) - 3.74863 (61.6102 - 3.38 t + t^2)
(2.8561 - 3.38 t + t^2) - 7.49726 s (-1.69 + t) (26.5209 - 2.43421*10^-16 t + t^2) +
MSR^4 (-2.14208 s^2 + s (-66.0669 - 29.4535 t) - 27.3115 (0.639919 + t)
(4.46322 + t)) + MSR^2 (s^2 (7.24021 + 12.8525 t) + 14.9945 (-1.69 + t)
(19.1767 + 4.34571 t + t^2) + s (177.421 + 86.8826 t + 23.5628 t^2)))/
((1.69 - 1. t)^2 (1.69 + 2. MSR^2 - 1. s - 1. t)^2 v45^4) + (GG^2
(-1383.72 + 71.6685 MSR^6 + MSR^4 (-242.24 - 35.8343 s - 143.337 t) +
s^2 (-60.5599 - 35.8343 t) + 1637.54 t - 484.479 t^2 - 35.8343 s (-1.69 + t)
(11.83 + t) + MSR^2 (71.6685 (-1.69 + t) (11.83 + t) + s
(242.24 + 143.337 t))))/(s (1.69 - 1. t) (-1.69 - 2. MSR^2 + s + t) v45^2)


Where GG, v45, MSR, t and s are free variables - I 'd like to leave them as unknowns.

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Do you know a priori that this expression has a significantly simpler form? –  Mr.Wizard Aug 29 '13 at 22:08
Collect[Expand[yourOutput], 1/(v45^4) ] might be a start –  TomD Aug 30 '13 at 15:12