Fee (f):
470=f+7(1.2f)
470=f+8.4f
470=9.4f
f=470/9.4
f=50
Fee is 50$
Now, to find how much he charges an hour (h):
h=1.2f
h=1.2×50 (we just found out that fee charge is 50$)
h=60
He charges 60$ an hour.
Now lets check:
Does 7(60)+50 equal to 470?
Yes. So, fee is 50$ and hour charge is 60$.
Hope this helps.