Tim 3 phan so khac nhau ,biet tong cua phan so thu 1 va phan so thu 2 la 7/8 ,tong cua phan so thu 2 va phan so thu 3 la 8/7 ,tong cua phan so thu 1 va phan so thu 3 la 8/9.
cho hai day so :
1 , 4, 7 , 10 , 13 , ....
1/2 , 2/3 , 3/5 , 5/8 , 8/13 ,.....
a, hay neu quy luat va viet hai so hang tiep theo cua moi day so tren .
b, so 2005 co phai la so hang cua day so 1,4,7,10,13 ... khong ? vi sao ?
tim cac phan so bang nhautrong cac phan so day :2:5 ; 4:7; 6:15; 8:14; 16:28; 24:60;
bai 1. cho day so 2, 4, 6, 8, 10... 1992
a, hoi day so do co bao chu so.
b, tim chu so 2000 cua day.
viet cac phan so sau day theo thu tu tu be den lon
a ) 5/6 ; 14/21 ; 8/7 ; 51/42 ; 15/14
b) 1/2 ; 5/6 ; 4/5 ; 7/8 ; 6/7 ; 8/9
tra loi xong nho kb voi mk nha , ai nhanh mk tk
Trung binh cong cua 2 phan so = 7/8 Nếu tang phan so thu hai len gap 3 lan thi trung binh cong cua chung =17/8 Tim 2 phan so do
1,
Tim 1 phan so biet tu so hon mau so 8 don vi va ti so cua tu so va mau so la 5/3
2,
Hay viet cac phan so co mau so la 9 va nam giua 2 phan so 6/18 va 16/27
3,
Hay viet 4 phan so khac nhau sao cho moi phan so lon hon 5/6 va be hon 6/7
1) Mot hinh chu nhat co chu vi la 320 cm . Biet neu viet them chu so 1 vao ben trai so do chieu rong thi duoc so do chieu dai . Tim dien tich cua hinh chu nhat ?
2) Viet cac phan so sau day thanh tong 3 phan so sao cho moi phan so co tu so la 1 , mau so khac nhau
a) 11/26 ; b) 7/8
1) Cho 2 so khac nhau . So lon co chu so hang chuc la 7 , chu so hang don vi la 3 . Neu xoa chu so 7 va chu so 3 do ta duoc so be . Hieu cua 2 so do la 9082 . Tim 2 so do ?
2)So sanh A va B :
A = 2008/987654321 + 2009 / 246813579 . Day la phan so
B = 2009/987654321 + 2008 / 246813579 . Day la phan so