$*$Please show excel formulas used to get the answer $($PMT$,$ FV$,$ PV$,$ etc.$)$

You purchased your home $5$ years ago for $$720,000$ using a $30-$year FRM with a balance of $$550,000$ and a $7\mathrm{.}25\%$ interest rate.

Now rates have fallen so you want to do a rate refi for the exact same amount that you have left on your old mortgage today

After shopping around, you find two options:

Refi option $125-$year FRM with an interest rate of $4\mathrm{.}5\%$ and $$13,500$ in fees and $2$ points

Refi option $225-$year FRM with an interest rate of $4\mathrm{.}9\%$ and $$13,500$ in fees and no points

Your outside option is $3\%$

a$)$ Should you refi, and if so$,$ which option would you select if you hold your mortgage for another $25$ years?

b$)$ Should you refi, and if so$,$ which option would you select if you hold your mortgage for another $4$ years?