550-1,50(5*4)

Let's solve the expression step by step:

1. Start with the innermost parentheses: \( 5 * 4 = 20 \).
2. Now substitute that back into the expression: \( 550 - 1.50(20) \).
3. Next, calculate \( 1.50 * 20 = 30 \).
4. Finally, subtract that from 550: \( 550 - 30 = 520 \).

So, the result of the expression \( 550 - 1.50(5*4) \) is \( 520 \).