24.75 feet was the initial height of the bird. We can use definitions and corresponding addition here:
The word descending is denoted as something or someone that moves or slopes downward. Our equation will look like so, with x representing the initial height of the bird:
x - 8.25 = 16.5 (or in other words, 16.50)
Now that we have our equation set up, we can use inverse operations to solve.
16.50 + 8.25 = 24.75
Since doing addition gave us a total of 24.75, we know that the initial height of the bird is 24.75 feet. To check our work, we can plug this number in for x:
24.75 - 8.25 = 16.50
When calculating, this equation is true. Therefore, the initial height of the bird is 24.75 feet. If you need extra help, do not hesitate to let me know and I will gladly assist you.