. Use an induction argument to prove that: For all integers n 24, 2" Zn Proof: We proceed by induction. Since 224, the inequality holds for n=4. Assume that 2K2 K where K24. we show that 2*+ (k+) = K +2k+l. observe that K+= 2.2k 22K= K+K K+K-KK+4K 2 = K+2k +2K2 K +2k+8 > K+2K+1= (K+1) Therefore, 2K+ (K+1) . By the Principle of Mathematical induction, 2"n for every integer 124.