tinh nhanh 1/4*3+1/4*5+1/6*5+1/7*6+1/8*7+1/9*8+1/10*9=
tinh 1/4+1/6+1/8=
tinh nhanh phan so
1/2*3+1/3*4+1/4*5+1/5*6+1/6*7+1/7*8
1+2+3+4+5+6+7+8+9 tinh bang canh tinh meo nha
tinh bang cach thuan tien nhat
1/2+1/6+1/12+1/20
1/2+1/6+1/12+1/20+.........+19900
1/2+1/3+1/4+1/8+1/16
1/2+1/3+1/4+1/8+1/16+.......+1/512
tinh
a 7/15 + (5/6 - 1/3) =
b 4/7 *21/16 : 5/8 =
c 15/8 - 4/9 * 6/8+ 1/6 =
d 5/12+(3/4 + 2/3 ) : 34/3 =
Tinh nhanh :
a . 1/4 + 2/5 + 6/8 + 9/15 + 8/1
b . 15/31 * 16/43 + 15/31 * 27 4
1/3+1/4+1/5+1/6+1/7+1/8 nhu the nao voi 2
khong tinh ket qua ma so sanh
Tinh: 1/3+3/4+2/6 3/7+5/14-1/8 5/4-1/2+3/8