Erin bought 3 more pounds of apples than katie. together katie and erin bought 13 pounds of apples. how many pounds of apples did katie buy?

(big pts for the first to answer and i will give u a medel for the first to give a good ! so )

The length of each stair is 11 inches. what is the rise, r, for each stair? round to the nearest inch. 2 inches 7 inches 17 inches 24 inches

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

Icould really use some with this question.