What interger is equivelent to 9^3/2

How can you decide witch operations to use to slice a two step equation

The table below shows the height of a ball  x  seconds after being kicked.  what values, rounded to the nearest whole number, complete the quadratic regression equation that models the data? f(x)  =  x2  +  x  +  0based on the regression equation and rounded to the nearest whole number, what is the estimated height after 0.25 seconds?   feet

True or false look at the picture pls : /