Use properties of operation to subtract

To simplify the expression \((P - 3) - (2.4 + 2P)\), we can use the properties of operations. Here's how to do it step by step:

1. Distribute the negative sign into the second part of the expression:
\[
(P - 3) - (2.4 + 2P) = P - 3 - 2.4 - 2P
\]

2. Combine like terms. The terms involving \(P\) are \(P\) and \(-2P\), and the constant terms are \(-3\) and \(-2.4\):
- Combine the \(P\) terms:
\[
P - 2P = -P
\]
- Combine the constant terms:
\[
-3 - 2.4 = -5.4
\]

3. Putting it all together, we get:
\[
-P - 5.4
\]

Thus, the simplified expression is:
\[
-P - 5.4
\]