To solve this expression, we need to follow the order of operations (PEMDAS/BODMAS).

First, we need to simplify the division:

450/2 = 225

Now, we can substitute this value back into the expression:

2.75 + 225/2

Next, we need to simplify the division again:

225/2 = 112.5

Finally, we can substitute this value back into the expression:

2.75 + 112.5

Adding these two numbers together gives us the final result:

2.75 + 112.5 = 115.25