Answer:
I'm pretty sure step 1 Is where he made the mistake
<u><em>Parallelogram </em></u>
If you need more help I would be glad to help!:D
~"AB84"~
(y-2)4 + 21
You subtract two because the 21 accounts for it and then whatever you have left multiplied by 4 and added to 21 is the amount of years after conversion.
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