tim so hoan chinh trong cac so sau va giai thich vi sao so do la so hoan chinh?:

                    496, 12,  748, 10

mot so tu nhien duoc goi la so hoan chinh. neu tong tat ca cac uoc cua no gap 2 lan so do. hay tim mot vai so hoan chinh!

MOT SO TU NHIEN GOI LA SO HOAN CHINH NEU TONG TAT CA CAC UOC CUA NO GAP HAI LAN SO DO. HAY NEU RA MOT VAI SO HOAN CHINH.VD:6LA SO HOAN CHINH VI U(6)={1;2;3;6} VA 1+2+3+6=12

1,

tim tap hop cac U(28)

2,tim x

x-1=U(12)

3,tim x

2+1=U(28)

4,

tim cac hop so >50 va khong vuot qua 90

5,

tim cac so nguyen to co 2 chu so

tim tat ca cac so nguyen to p sao cho 5^p+12^p la so chinh phuong

1the vi ngu cho cac cau sau de hoan chinh cac cau

tim a de cac so sau la so chinh phuong:a2+a+43

tim so co 2 chu so biet rang neu lay tong cac chu so cong voi tich cac chu so cua so do thi bang chinh no.

Tim so chinh phuong co 4 chu so duoc viet boi cac chu so 7;4;2;0