Please I need help ASAP

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)

2x minus y equals 6, x plus y equals negative 3

Tim earns $120 plus $30 for each lawn he mows.write an iniqualityvto represent how many lawns he needs to mow to make more than $310