Wir haben eine Investition von tausend Euro gemacht.
We made an investment of a thousand euros.
Diese Investition wird sich bald auszahlen.
This investment will pay off soon.
Note
The article is part of the word: die Investition. That way you learn the gender with it.
Remember die Investition for good. ripiti brings the word back just before you forget it, with these sentences. Free, no account needed, works offline.