(2-m)(-m-2)-(5+m)²

To simplify the expression \((2-m)(-m-2)-(5+m)^{2}\), let's break it down step by step. 1. **Expand the first part \((2-m)(-m-2)\)**: \[ (2-m)(-m-2) = 2 \cdot (-m) + 2 \cdot (-2) + (-m) \cdot (-m) + (-m) \cdot (-2) \] This results in: \[ = -2m - 4 + m^2 + 2m \] Now, combine the like terms: \[ -2m + 2m - 4 + m^2 = m^2 - 4 \] 2. **Expand the second part \((5+m)^{2}\)**: \[ (5+m)^{2} = 5^2 + 2 \cdot 5 \cdot m + m^2 = 25 + 10m + m^2 \] 3. **Put it all together**: Now, substituting our expansions into the original expression gives us: \[ (2-m)(-m-2)-(5+m)^{2} = (m^2 - 4) - (25 + 10m + m^2) \] 4. **Distributing the negative sign**: \[ = m^2 - 4 - 25 - 10m - m^2 \] 5. **Combine like terms**: The \(m^2\) terms cancel out: \[ = -4 - 25 - 10m = -29 - 10m \] So, the final simplified expression is: \[ \boxed{-29 - 10m} \]