Các câu hỏi tương tự
Cho A = 2+2^2+2^3+2^4+...+2^60. Chung to rang A chia het cho 3;7va 15
cho A = 2+ 2^2+2^3+2^4+....+2^60
chung to rang A chia het cho 3
Chứng tỏ rằng: 1/3^2+1/4^2+1/5^2+...+1/60^2<4/9
cho A= 2+22+23+24+25+..........+260
chung to rang A chia het cho 3,7,15
chung to rang:
A= 2 + 2^2 + 2^3 + 2^4 + ...+ 2^90
chung minh rang
A= 2 mũ 1+ 2 mũ 2+ 2 mũ 3+ ....... +2 mũ 60
a] chung minh rang A chia hết cho 7
b] tìm n biết A+2 =2 mũ n
B=\(^{2+2^2+2^3+...+2^{59}+2^{60}}\)
a, chung to rang B chia het cho 3,5,7
b,tim chu so tan cung cua B
Cho bieu thuc A = 2 + 22 + 24 + 25 + ........+260
chung to rang A chia het cho 7
cho S = 2+ 22 + 23+24+25+26+27+.........+ 260
chung to rang S chia het co 3;7
tinh S