We can find the vertex coordinates for this quadratic equation using the next formulas:

Where the values for a, b, c are obtained by looking at the values of these coefficients in the general quadratic expression:

Then, we have that:
a = 1, b = -3, c = -10.
Then, to find the x-coordinate of the quadratic equation, we have:

To find the y-coordinate, we have:

Then:

Therefore, the value for the y-coordinate is -12.25 (in decimal form).
In summary, we have that the vertex coordinates for the quadratic equation x²-3x-10 are (1.5, -12.25).