Solve for a side in right triangles

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

The volume of a cube is 8 in to the 3rd power. how long is each side?

The price of an item has been reduced by 30%. the original price was $30. what is the price of the item now ?