A = 22009 - 22008 - 22007 - .... - 22 - 2 - 1
= 22009 - ( 22008 + 22007 + .... + 22 + 2 + 1 )
Đặt B = 1 + 2 + 22 + .... + 22008
2B = 2(1 + 2 + 22 + .... + 22008 )
= 2 + 22 + 23 + .... + 22009
2B - B = ( 2 + 22 + 23 + .... + 22009 ) - ( 1 + 2 + 22 + .... + 22008 )
B = 22009 - 1
=> A = 22009 - ( 22009 - 1 ) = 1
Vậy A = 1
Tinh nhanh A=2^2009-2^2008-2^2007-.....-2^2-2^1-1
Tính A= 2009/2+2008/(2^2)+2007/(2^3)+...+3/(2^2007)+2/(2^2008)+1/(2^2009)
Tính nhanh :a)2/5+4/5 nhân 5/2
b)2008/2009-2009/2008+1/2009+2007/2008
2. So sánh A và B:
A= 2006/2007 - 2007/2008 + 2008/2009 - 2009/2010
B=-1/2006*2007 - 1/2008*2009
tinh A=1-2+3+4-5-6+7+8-9-...+2007+2008-2009-2010
Tính nhanh:a)2/5+4/5x5/2
b)2008/2009-2009/2008+1/2009+2007/2008
tinh nhanh
a) 36*17-8.7*25+64*17-0.87*650
b) 2009*14+1994+2007*2008/2008+2008*505+504*2008
c) 1*1+2*2+3*3+4*4+5*5+...+98*98
TÍNH NHANH :
A= 2^2009 - 2^2008-2^2007 -....-2^2 - 2^1 - 1
tinh theo cach hop li
[-1]+2+[-3]+4+[-5]+6+.....+[-2005]+2006+[-2007]+2008+[-2009]+2010
