Hi there!
We could solve the equation by dividing each numerator.
We subtract the exponent when we divide x.
ex) 10x³/2x = 5x² because 3-1=2.
Divide -40x³ by -4x first : 10x²
Then divide -12x by -4x : 3x
Lastly divide 16x by -4x : -4
We can add all of them together.
10x² + 3x - 4
So your answer is 1. 10x² + 3x - 4.
Hope this helped :)