cho tong S=1+3+5+....+2015. tinh s chung to S la so chinh phuong a tim cac uoc nguyen to hac nhau cua S
CM A ko la so chinh phuong va A=5+5^2+.....+5^200
cho tong S= 1+3+5+....+2009+2011
a) tinh S
b chung to S la so chinh phuong
c tim cac uoc nguyen to khac nhau cua S
M=1+5+5^2+5^3+5^4+...........+5^2013.
em hay chung to:4M+1 la 1 so chinh phuong
a, so co tong cac chu so la 2004 khong la so chinh phuong
b, so co tong cac chu so la 2006 khong la so chinh phuong
c, n = 20044+20043+20042+23 khong la so chinh phuong
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
a) cho A = 1+3+5+7+...+(2n+1) Voi n thuoc N
chung to rang A la so chinh phuong
b)B=2+4+6+8+...+2n voi n thuocN
so B co phai la so chinh phuong ko
tim số nguyen duong nho nhat thoa man mot phan 2 so do la so chinh phuong,mot phan 3 so do la luy thua bac 3 cua 1 so nguyen, mot phan 5 so do la luy thua bac 5 cua 1 so nguyen
Cho A = 5+52+53+...+5100
a)so A la so nguyen to hay hop so
b)so A co phai la so chinh phuong khong?