how would you solve this question

"When comparing GDP from one year to another, you need to adjust each year's GDP for any inflation that occurs during that year. To do this, you need to find real GDP. To find real GDP, or the value of GDP that takes into account any price changes in the period, use this formula:

You found the nominal GDP for two years in part c, but you will need to find the value of the deflators before you can use the formula. Price deflators neutralize any inflation that happened that year. Using this table ofprice deflator data, find the price deflators for gross domestic product (line 1) for the fourth quarter (IV) in the years you used in part c and record them in the table."

The numbers are:

GDP 2019 - 20.94 trillion

GDP 2020 - 21.43 trillion