Please solve this!! 3+n/9=6

Algebra 1: unit 6 part 2 of test a) the table shows a linear function. x 0 1 2 3 5 13 21 29 37 45 53 (a) determine the difference of outputs of any two inputs that are 1 unit apart. show your work. (b) determine the difference of outputs of any two inputs that are 2 units apart. show your work.

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

Which equation results from adding the equations in this system? x+6y=9 and -x+2y=-15