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

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

1. **Combine the \(x^2\) terms:**

\[
14x^2 + 0.75x^2 = 14.75x^2
\]

2. **Combine the \(x\) terms:**

\[
-3x + 2x = -1x \quad \text{(or simply -x)}
\]

3. **Combine the constant terms:**

\[
2.25 - 14 = 2.25 - 14 = -11.75
\]

Now, putting it all together:

\[
(14x^2 - 3x + 2.25) + (0.75x^2 + 2x - 14) = 14.75x^2 - x - 11.75
\]

Thus, the simplified expression is:

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