tim so tu nhien n co hai chu so sao cho 2n la mot binh phuong cua mot so tu nhien 3n la lap phuong cua mot so tu nhien
tim so nguyen duong n nho nhat sao cho n/2 la binh phuong cua mot so nguyen va n/5 la lap phuong cua 1 so nguyen
tim 1 so co 2 chu so . biet so do la lap phuong cua so tu nhien va tong cac chu so cua no bang binh phuong cua mot so tu nhien
Tim cac so tu 1 den 30 sao cho no la
a Binh phuong cua mot so tu nhien
b Lap phuong cua mot so tu nhien
tim cac stn n de Q=1!+2!+3!+....+n! la mot so chinh phuong.
tim stn n khac 0 sao cho : 1!+2!+3!+....+n! la 1 so chinh phuong
tim stn n khac 0 sao cho : 1!+2!+3!+....+n! la 1 so chinh phuong
1. cho 4 stn a lon hon hoac bang b, b lon hon hoac bang c, clon hon hoac bang d.
CM:(a-b)(a-c)(a-d)(b-c)(b-d)(c-d)
2. CM: co the tim dc 1 stn k sao cho: (1997^k)-1 chia het cho 10^4
3. tong cac chu so cua 1 so chinh phuong co the bang 1995 dc k?
4. tong cua 1995 stn khac 0 dung bang 1995. Hoi UCLN cua chung la bao nhieu?
tim tat ca cac stn n sao cho ( 3n + 1 ) la 1 so chinh phuong
