Eight less than some number is ten

How do i start to solve? would appreciate a walk-thru! a bird sitting 16ft above the ground in an apple tree dislodges an apple. after how many seconds does the apple land on the ground? (assuming that no branches will interfere with it's fall)

Aline passes through (1,-5) and(-3,7) write an equation for the line in point slope form rewrite the equation in slope intercept form

This is about circle theorems. someone asap : (