How do you write 8 thousands 4 hundreds 2 ones in standard form

Quick translate "x is 12 units from 20" into an equation. what are the values of x being described? if you can answer any of my other questions that'd be great too

Which recursive formula can be used to determine the total amount of money earned in any year based on the amount earned in the previous year? f(n+1)=f(n)+5

Inez has a phone card. the graph shows the number of minutes that remain on her phone card a certain number of days.