C=4+22+23+24+...+22005
=22+22+23+...+22005
=>2C=23+23+24+...+22006
=>2C-C=(23+23+24+...+22006)-(22+22+23+...+22005)
=22006+23-22-22=22006+8-4-4=22006
=>ĐPCM
C=4+22+23+24+...+22005
=22+22+23+...+22005
=>2C=23+23+24+...+22006
=>2C-C=(23+23+24+...+22006)-(22+22+23+...+22005)
=22006+23-22-22=22006+8-4-4=22006
=>ĐPCM
Cho A=4+2^2+2^3+2^4+...+2^2002.Chung minh rang A la mot luy thua cua 2
cho B=3+3^2+3^3+.....+3^2005.Chung minh rang :2B +3 la luy thua cua 3
chung minh rang a la mot luy thua cua 2; a=4+22+23+24+......+220
bai 1:
a, Cho B= 3+32+33+...+32005. Chung minh rang : 2B +3 la luy thua cua 3
b, Cho D= 5+53+55+...+597+599. Chung minh rang : 24 x B+5 la luy thua cua 5.
Ai nhanh mik k
chung minh rang A la 1 luy thua cua 2 voi A=A+2^2+2^3+2^4+...+2^20
Cho A =3 + 32 + 33 + ... + 3100
Chung minh rang 2A + 3 la mot luy thua cua 3
cho B =3+32+33+......+32005.chung to rang2B+3 la mot luy thua cua 3
cho A= 3+3^2+3^3+...+3^100
chung minh: 2.A+3 la mot luy thua cua 3
cho biieu thuc
A=2+2^2+...+2^200
c/m rang A+2 la mot luy thua cua 2
c/m A chia het cho 30
giai nhanh ho minh