Subtract 8√23 - √23

The correct answer is 7√23.

To subtract 8√23 - √23, you can combine the terms with the same radical (√23) and subtract their coefficients. This gives us:

8√23 - √23 = (8 - 1)√23 = 7√23

Therefore, the correct answer is option 4: 7√23.

To subtract 8√23 from √23, you can consider them as like terms since they both have the same radical (√23).

The expression 8√23 - √23 can be simplified by combining the coefficients and leaving the radical term unchanged.

The coefficient of the first term, 8, minus the coefficient of the second term, 1, is equal to 7.

Therefore, the simplified form of 8√23 - √23 is 7√23.

So, the correct answer is option 2: 7√23.