hey please help me with these extension questions thanx!!

1)simplify:

(2/1!)-(3/2!)+(4/3!)-(5/4!)+...+(1998/1997!)-(1999/1998!)

where k! is teh product of all integers from 1 up to k

AND

2) P and Q are the point on the sides AB and BC of a triangle ABC respectively such that BP=3PA and QC=2BQ. K is the midpoint of the segment PQ. Prove that the area of the triangle AKC is equal to 11S/24 where S is teh area of the triangle ABC

thanx everyone