300•(27+123)-(3456+1544)•4

To solve the expression \( 300 \cdot (27 + 123) - (3456 + 1544) \cdot 4 \), we will follow the order of operations:

1. Calculate the expressions inside the parentheses:

   • \( 27 + 123 = 150 \)
   • \( 3456 + 1544 = 5000 \)

2. Now substitute these values back into the expression: \[ 300 \cdot 150 - 5000 \cdot 4 \]

3. Next, perform the multiplication:

   • \( 300 \cdot 150 = 45000 \)
   • \( 5000 \cdot 4 = 20000 \)

4. Now, subtract the second product from the first: \[ 45000 - 20000 = 25000 \]

So, the final result of the expression is \( \boxed{25000} \).