Combine like terms

Let's simplify the expression \(2x^2 + 5x - 10 - 2(3x^2 + x)\) step by step.

1. Distribute the \(-2\) to the terms inside the parentheses:
\[
-2(3x^2 + x) = -6x^2 - 2x
\]

2. Rewrite the entire expression:
\[
2x^2 + 5x - 10 - 6x^2 - 2x
\]

3. Now, combine like terms:

- Combine the \(x^2\) terms:
\[
2x^2 - 6x^2 = -4x^2
\]

- Combine the \(x\) terms:
\[
5x - 2x = 3x
\]

- The constant term remains:
\[
-10
\]

4. Putting it all together:
\[
-4x^2 + 3x - 10
\]

So, the simplified expression is \(-4x^2 + 3x - 10\).

The correct answer is **b**: \(-4x^2 + 3x - 10\).