Write 3954 in expanded form using powers of 10

Which expression shows the sum of the polynomials with like terms grouped together

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)

Factor the expression using gcf 9b+45