Các câu hỏi tương tự
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 phan so A=63/3n+1 ( n thuoc N)
a. Voi gia tri nao cua n thi A rut gon duoc
b. Voi gia tri nao cua n thi A la mot so tu nhien
11111 co phai la so nguyen to khong .neu la hop so thi hay phan tich ra thua so nguyen to
cho tap hop A la tap hop cac so tu nhien chan lon hon 20 va be hon 30 B la tap hop lon hon 2 va be hon 33 so phan tu thuoc tap hop C thuoc B ma khong thuoc A
1/. X36y chia het cho 9, biet y là so nguyen to nho nhat?
2/. 6x3y chia het cho 3 , khi chia 5 dư 1
3/. x63y chia het cho 3, biet x khong phai la so nguyen to, cung khong phai la hop so
mot can phong hinh chu nhat co chieu rong la 5m va chieu dai la 9m.de lat nen gach men,tren thi truong co 3 loai gach men hinh vuong voi kich thuoc tung loai nhu sau:loai thu nhat co canh la 30cmloai thu 2 co canh la 40cmloai thu 3 co canh la 40cma,muon lat kin nen can phong tren bang cung 1 loai gach sao cho khong phai cat bat cu 1 vien gach nao thi phai chon loai gach nao trong 3 loai gach tren? vi sao? (cac vien gach duoc lat lien voi nhau,khong co mach ho)b,tinh tong so vien gach can dung th...
Đọc tiếp
mot can phong hinh chu nhat co chieu rong la 5m va chieu dai la 9m.de lat nen gach men,tren thi truong co 3 loai gach men hinh vuong voi kich thuoc tung loai nhu sau:
loai thu nhat co canh la 30cmloai thu 2 co canh la 40cmloai thu 3 co canh la 40cma,muon lat kin nen can phong tren bang cung 1 loai gach sao cho khong phai cat bat cu 1 vien gach nao thi phai chon loai gach nao trong 3 loai gach tren? vi sao? (cac vien gach duoc lat lien voi nhau,khong co mach ho)
b,tinh tong so vien gach can dung theo loai da chon o cau a
A la tap hop cac so co 3 chu so khac nhau lap tu cac so 1;3;6;9 va khong chia het cho 3 va khong chia het cho 2.so phan tu cua tap hop A la.
cho x =(2n + 1)(3n+2) voi n thuoc N*
hoi tich tat ca cac uoc cua x co phai la so chinh phuong khong? giai thich?
1/. X36y chia het cho 9, biet y là so nguyen to nho nhat?
2/. 6x3y chia het cho 3 , khi chia 5 dư 1
3/. x63y chia het cho 3, biet x khong phai la so nguyen to, cung khong phai la hop so