Hi I'm new to the forum so apologies if I've posted in the wrong section or my title is misleading.

My maths isn't great but I have a problem to solve using a pressure drop formulae 0.3=(800*160*300^2)/(7d^5.31)

So I need to solve for d to figure out my pipe diameter and I've got this far...

2.1d^5.31=11520000000 (Multiplying both sides by 7d^5.31)

d^5.31=5485714285.71 (Dividing both sides by 2.1)

This is as far as I've got and I'm unsure on the next step I wondered if somebody could point me in the right direction please? (Or point out I've gone wrong already if so)