: Cho S = 2. 1 + 2. 3 + 2. 3 ^2 + ... + 2. 3 ^2004 a) Thu gon S b) Tim chu so tan cung cua S. Tu do suy ra S khong phai la so chinh
phuong.
Cho S=1+3+32+33+....+330
Tim CS tan cung cua S roi suy ra S ko phai la so chinh phuong
Giup mk voiiiiiiiiiiii
cho S=2.1+2.3+2.32+....+2.32004
a)thu gon S
b)tim so tan cung cua S. tu do suy raS khong phai la so chinh phuong
Cho S = 1 + 31 + 32 + 32 + 33 + ... + 330
Tìm chữ số tan cùng của S, tu do suy ra S khong phai la so chinh phuong ?
1+3+3^2+......+3^30
tim c/s tan cung cua day tren
CMR day tren k la so chinh phuong
Cho S = 2011.72015+4.19766 mu2015
Tim chu so tan cung cua S.S co phai la so chinh phuong ko?
\(A=1+3^1+3^2+3^3+...+3^{30}\)
tim chu so tan cung cua A va chung minh rang A ko phai la so chinh phuong
tim so tu nhien lon hon 0 sao cho tong
1!+2!+...+n! la so chinh phuong
b)tim 1 so co 4 chu so sao cho so do vua la s chinh phuong vua la so lap phuong
mot so chinh phuong co chu so hang chuc la mot so le . tim chu so tan cung cua so chinh phuong do