What number is exactly midway between 23 − √17 and 23 + √17?

Question

What number is exactly midway between 23 − √17 and 23 + √17? What number is
exactly midway between [−b −((√b^2) − 4ac))]/2 and [−b +((√b^2) − 4ac))]/2?

Answer 1

The number pairs you state are in the form of A+B and A-B. Their average is A.

For the first that means 23, and for the second that means -b/2.