Will give brainliest!!

Vince borrows $900 to buy a couch. He will pay off the loan by paying 1.5% simple interest for 2 years. Vince incorrectly calculates the amount he will pay back using the expression below. 900 + 900(1.015 . 2)

What is the correct amount Vince will pay back altogether? Explain the error in Vince's expression?