Graph y= -4/3x+8 I don’t understand this khan academy stuff

Evaluate the following expression 1/3^2

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

What is the location of point g, which partitions the directed line segment from d to f into a 5: 4 ratio? –1 0 2 3