Answer:
0.75 euros per dollar.
Explanation:
It is given that on a trip, you had to change your money from dollars to euros. 
You got 450 euros for 600 dollars. It means 
450 euros = 600 dollars 
We need to find the unit rate that describes the exchange. 
 
 
 
 
Therefore, the unit rate is 0.75 euros per dollar.