Which expression is equivalent to

Let's simplify the expression \((2x^2 + 6x - 3) + (x^2 - 7)\).

1. Combine the expressions: \[ 2x^2 + 6x - 3 + x^2 - 7 \]

2. Combine like terms:

   • Combine \(2x^2\) and \(x^2\): \[ 2x^2 + x^2 = 3x^2 \]
   • Combine \(6x\) (there's no other \(x\) term to combine with): \[ 6x \]
   • Combine the constant terms \(-3\) and \(-7\): \[ -3 - 7 = -10 \]

3. Putting it all together: \[ 3x^2 + 6x - 10 \]

Now let's compare that with the options provided:

A) \(x^2 + 4x - 10\)
B) \(4x^2 + 8x + 4\)
C) \(3x^2 + 4x - 10\)
D) \(3x^2 + 8x + 4\)

The closest match to our simplified expression \(3x^2 + 6x - 10\) is not listed as an option, but it seems like we can correct ourselves if we compare the options yet again correctly:

The correct and closest would be none of the options given, but mostly apt would be:

C) if we consider typographical errors made in transcription where it could be combined mistakenly. Make sure to confirm the expression input fully rather than having an error with the third option.

If the original question provided is directly from a source refer to it or contact the source for corrections and verifications needed.

But to sum up, the expression simplifies to \(3x^2 + 6x - 10\), a unique answer not directly shown in the choices given.