Simplify (14x2−3x+2.25)+(0.75x2+2x−14)

To simplify the expression \( (14x^2 - 3x + 2.25) + (0.75x^2 + 2x - 14) \), we will combine like terms.

1. **Combine the \(x^2\) terms:**
\( 14x^2 + 0.75x^2 = 14.75x^2 \)

2. **Combine the \(x\) terms:**
\( -3x + 2x = -1x \) or simply \(-x\)

3. **Combine the constant terms:**
\( 2.25 - 14 = -11.75 \)

Putting it all together, we have:

\[
14.75x^2 - x - 11.75
\]

Thus, the simplified expression is:

\[
\boxed{14.75x^2 - x - 11.75}
\]