Answer
The population of both countries will be $9,900,000$ in $2025.$
Work Step by Step
Let $ x=$ the number of years after 2000.
Population of Greece after x years = $10,600,000-28,000x $
Population of Belgium after x years = $10,200,000-12,000x $
We want to find x when these two are equal.
$10,600,000-28,000x=10,200,000-12,000x$
Combine like terms:
$400,000=16,000x$
Divide with $16,000$:
$ x=25$
25 years after 2000 (in 2025) they will have the same population, which is calculated by substituting $x=25$ into one of the expressions above.
$10,200,000-12,000(25)=9,900,000$
The population of both countries will be $9,900,000$ in $2025.$
