Answer:
Equation- s + 456 = 437 (I'm not completely sure if this is what your wanting but it is possible to solve the problem with this equation. if this isn't what you need I can write another)
Explanation:
s represents the starting height.
s + 456 = 437
first subtract 456 from either side, 437 - 456 = -19.
s = -19 (I'm not sure if this is correct it's been a few months since I've used variables for equations but I tried)