Answer:
425 + 165 = 590
Explanations:
To add two numbers using expanded notation, you break each of the numbers into their place value constitutents.
425 = 400 + 20 + 5
165 = 100 + 60 + 5
425 + 165 = (400 + 20 + 5) + (100 + 60 + 5)
425 + 165 = (400 + 100) + (60 + 20) + (5 + 5)
425 + 165 = 500 + 80 + 10
425 + 165 = 590