\(\dfrac{2}{3}\cdot\dfrac{4}{9}=\dfrac{2\cdot4}{3\cdot9}=\dfrac{8}{27}\)
\(\dfrac{2}{3}\cdot\dfrac{4}{9}=\dfrac{2\cdot4}{3\cdot9}=\dfrac{8}{27}\)
1 a, 3 va 1/5 - 2 va 1/6 + 1/5
b, 5 va 12/13 - 2 va 15/26 + 1/26
c, 7 va 1/12 + 1/12 - 6 va 1/4
2 tinh gia tri bieu thuc
a, 3 va 2/9 - [1 va 5/8 + 1 va 2/9 ] - 3/8
b, 4 va 2/5 - 1 va 3/7 - 1 va 4/7 + 1/5
c, 1 va 9/12 - 5/4 - 1/2
3 tinh
a, 6 nhan 7 nhan 8 nhan 9 nhan 1 tren 18 nhan 16 nhan 14 nhan 12 nhan 2
b, 4 nhan 15 nhan 9 nhan 24 tren 3 nhan 12 nhan 8 nhan 5
4 rut gon cac phan so
a, 96/150 ; 255/408 ; 630/224
b, 1515/1717; 352352/470470; 200620062006/200520052005
5 so sanh cac phan so
a, 7/9 va 9/7 ; b, 135/120 va 13/8; c, 3535/4848 va 5/8 ; d, 650650/480480 va 222222/144144
6, so sanh hai phan so
a, 2005/2006 va 2006/2007 ; b, 2008/2007 va 2007/2006
cac ban lam tung buoc nha
9/4 - y nhan 5/6 = 1/2 +2/3
x nhan 3/4 bang 1/5 nhan 9/8
Tinh gia tri cua bieu thuc :
3/4 nhan 8/9 nhan 15/16 nhan ...nhan 99/100 =
0 nhan 9+8+7+6+5+4+3+2+1
9/14 nhan y ( 5/7 - 3/14 ) nhan 4/7
4.65 nhan 2 nhan 6 cong 9 nhan 4 nhan 456.32 cong 456.32 nhan 18 cong 456.32 nhan 7 nhan 4 cong 6 nhan 456.32
1 nhan 2 cong 2 nhan 3 cong 3 nhan 4 ... cong 39 nhan 40
45 phut 21 giay nhan 2
16 gio 25 phut nhan 4
4gio 13 phut nhan 4
21 phut 15 giay nhan 3
12 ngay 6 gio nhan 3
13 nam 2 thang nhan 4
5 gio 16 phut nhan 4
15 phut 23 giay nhan 6
21 ngay 8 gio nhan 7
20 nam 8 thang nhan 4
5 phut 20 giay nhan 3