A= \(2^0+2^1+2^2+...+2^{50}\)
\(\Rightarrow\)2A =2(\(2^0+2^1+2^2+...+2^{50}\))
\(\Rightarrow\)2A= \(2+2^2+2^3+2^4+...+2^{51}\)
\(\Rightarrow\)2A-A= (\(2+2^2+2^3+2^4+...+2^{51}\))-(\(2+2^2+2^3+2^4+...+2^{50}\))
\(\Rightarrow\)A= \(2^{51}-1\)
A = 2mu 0 + 2 mu 1 + 2mu 2 + ...+ 2 mu 50
(5 mu 4 + 4 mu 7) (8 mu9 - 2mu 7) (2mu 4-4 mu 2)
Nay giup Minh nhanh 1chut can ban oi .2cau nay be la town nhanh can .a)2mu x cong mu 2=2mu 50:8
A=1/2 +1/2mu 2+...+1/2 mu 15
cho a= 2mu 2+ 2 mu 3+2mu4+....+2mu 12
chung to rang a chia hết cho 39
cho s= 2+2 mu 2+2 mu 3+ 2mu 4 +....+2 mu 99 +2 mu 100
a, tinh S
b,CHUNG MINH RANG S CHI HET CHO 3
Viet tong A bang 2mu 2+2 mu 3+2 mu 4+...+2 mu 20 duoi dang luy thua cua 2
bai1 12mu n+1 + 11mu n+2 chia hết cho 133
bai2 3mu n+2 -2mu n+2 + 3 mu n -2mu n
so chinh phuong la so bang binh phuong cua mot so tu nhien ( vi du 0 ,1,2,4,9,16,...0) moi tong sau day co so chinh phuong ko
a) 1mu 3 +2 mu 3
b)1mu 3+2mu 3 +3 mu 3
c)1 mu 3+ 2 mu 3 + 3 mu 3 +4 mu 3
tai minh ko biet go dau mu !
