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 tat ca cac uoc chung cua hai so 3n+11va n + 2 voi n thuoc N*
Cac Gia Tri Sau Co Phai So Chinh Phuong Khong
A=2+2^2+2^3+...+2^197
B=x^2012+(x+1)^2
B2
Tim n
n^2×2178 la so chinh phuong
1) Tim tat ca cac uoc chung cua hai so tu nhien lien tiep .
2) Tim tat ca cac uoc chung cua 5n + 6 va 8n + 7 (n thuoc N)
3)Mot khoi hoc sinh xep hang 4 , hang 5 ,hang 6 deu thua 1nguoi nhung xep hang 7 thi vua du .Biet so hs chua den 400 nguoi .Tinh so hs
4)Goi X la tap hop cac hoc sinh thich ca hat cua lop 6A .Tap hop Y la tap hop cac hoc sinh thic da bong cua lop 6A .Tap hop X giao Y bieu thi tap hop nao.
a) cho A = 1 + 3 + 5 + 7 +......+(2n + 1) Voi n thuoc N
chung to rang A la so chinh phuong
b) cho B = 2 +4+6 + 8 + ....+ 2n Voi n thuocN
so B co the la chinh phuong ko
neu co so tu nhien n sao cho k =n^2 thi ta noi so k la so chinh phuong tim tat ca cac so ab saocho (ab+ba) la so chinh phuong
1+3+5+.......+(2n-1) , n thoc so tu nhien khac 0 . n co phai la so chinh phuong khong
a, Neu A la con cua B thi voi moi x thuoc a, ta co x thuoc B
b, De chung to A la con cua B ta phai chung to voi noi X thuoc A thi X thuoc B
c, quy uoc tap hop rong la tap hop con cua moi tap hop
d,de chung to a khong phai tap hop con cua b, chi can neu ra 1 phan tu thuoc a ma khong thuoc b
Cho A=5+5^2+5^3+...+5^2016
a, A la hop so hay so nguyen to
b,A co phai la so chinh phuong khong ?
giup minh giai voi nha cac ban \(\)