To simplify the given expression [tex]\(\left(-x^2 + x\right) + \left(4x^2 - x - 1\right)\)[/tex], follow these steps:
1. Distribute any signs (if necessary):
In this case, everything is already distributed, so we can move to combining like terms directly.
2. Combine like terms:
- Combine the [tex]\(x^2\)[/tex] terms:
[tex]\[
-x^2 + 4x^2 = 3x^2
\][/tex]
- Combine the [tex]\(x\)[/tex] terms:
[tex]\[
x - x = 0
\][/tex]
- Combine the constant terms:
[tex]\[
-1
\][/tex]
3. Write down the simplified expression:
[tex]\[
3x^2 - 1
\][/tex]
Thus, the simplified form of the expression [tex]\(\left(-x^2 + x\right) + \left(4x^2 - x - 1\right)\)[/tex] is:
[tex]\[
3x^2 - 1
\][/tex]
Therefore, the correct answer is:
[tex]\[
\boxed{3x^2 - 1}
\][/tex]
So, the correct option is:
[tex]\[
\text{A. } 3x^2 - 1
\][/tex]
