Answer:
2
Step-by-step explanation:
The constant -h is half the x-coefficient -4, so is -2. That makes h = 2.
The square of the binomial (x-h) is ...
... (x -h)² = x² -2hx +h²
Comparing x-terms, you see that ...
... -2xh ≡ -4x
... h = (-4x)/(-2x) = 2
