2x^2-5x=-1 use quadratic formula to solve equation and simplify answer completely

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

If square root x = -7, then x= -49 true or false

Use sigma notation to represent the following series for 9 terms.