P=25 watts W=5000 Joules t=? Formula=____________ Substitution=____________ Answer with unit of measure=__________

I know what I need to do, and I don't want the answer, but what I don't understand is the formula. I don't know how to get the formula needed.
I know that when solving for the power (p) the formula is p= work (w) divided by time (t).
the power is 25 watts
the work is 5000 joules
the time is unknown.
I don't want the solved answer i just want the formula of p=w/t when solving for t,
and also the formula when solving for w.

Please help.