Step 1: Figure out how many years 2020 is after 1998
2020 is 22 years after 1998, therefore we should plug in 22 for x.
Step 2: Plug in known values
The only unknown variables in this equation are S and x. We just found out what x is, which leaves S for us to figure out by solving.
S - 1.5(22) = 5.1
Step 3: Solve
Now, all that's left to do is solve for S.
S - 1.5(22) = 5.1
S - 33 = 5.1
S = 38.1
Answer: 38.1 billion dollars
Hope this helps!
