What is the additive inverse of th polynomial -9xy2+6x2y-5x3?

I’m stuck on this i don’t understand.

An architect is designing a water fountain for a park she uses the given function to model the water jet flowing from the fountain nozzles where h(x) gives the height of the water jugs in feet x feet from the starting point h(x)=-1/20x+x+15

M the table below represents a linear function f(x) and the equation represents a function g(x): x f(x)−1 −50 −11 3g(x)g(x) = 2x − 7part a: write a sentence to compare the slope of the two functions and show the steps you used to determine the slope of f(x) and g(x). (6 points)part b: which function has a greater y-intercept? justify your answer. (4 points)