Answer:
(x - 2.5)^2 - 30.25.
Step-by-step explanation:
y = x^2 - 5x - 24
Divide -5 by 2 and complete the square:
y = (x - 2.5)^2 - 6.25 - 24
y = (x - 2.5)^2 - 30.25.
