unit problem

[kenan2]

Hello.

I have this unit problem.. Plz help. 

[AlanStevens]

You haven't defined superscript n.

Alan

PS It's usually best to upload your worksheet, not just an image.

[Werner_E]

The units in your first equation don't balance, neither if we assume n=2, nor for any other value of n.

The left hand side is of dimension "length", the right hand side pressure^n * length^(n/2)

[Fred_Kohlhepp]

Fatigue crack growth using Paris' parameter can be a bit of a challenge.  See if the attached can give you a place to start from.