Cách giải:
4/7 : 2/5 + 3/7 : 2/5 - 7/9
= ( 4/7 + 3/7 ) : 2/5 - 7/9
= 1 : 2/5 - 7/9
= 5/2 - 7/9
= 31/18. **** cho mình nha bạn.
Cách giải:
4/7 : 2/5 + 3/7 : 2/5 - 7/9
= ( 4/7 + 3/7 ) : 2/5 - 7/9
= 1 : 2/5 - 7/9
= 5/2 - 7/9
= 31/18. **** cho mình nha bạn.
Tinh Nhanh:
6 2/7 + 7 3/5 + 8 6/9 + 9 1/4 +2/5 + 5/7 + 1/3 + 3/4 + 1967
Tinh nhanh
A=1/1*2+1/2*3+1/3*4+1/4*5+1/5*6+1/6*7+1/7*8+1/8*9+1/9*10
bai 1:tinh nhanh hon so
a, 11 2/9+8 3/5+8 7/9+ 1 2/5
b, 4 2/3+5 1/2+1/3+4 1/2
c, 19 2/7+5 3/4+4 1/4-9 2/7
bai 2:hinh chu nhat co chieu dai 2 3/4m, chieu rong kem chieu dai la 1 1/2m. tinh chu vi va dien tich hinh chu nhat do.
1x2 + 2×3 +3×4 +4×5 +5×6+6×7+7×8+8×9+9×10
Ai tra loi nhanh va dung mk tk cho 2 cai
nho la tinh nhanh nha cac ban
tinh nhanh
3/2*4/7+3/7*3/2
12/5*4-4*7/5
3 tinh nhanh
7,48+7,48+99
(72-13.5 -7): (1+2+3+4+5+6+7+8+9+10)
BAI 1 : TINH NHANH BANG CACH THUAN TIEN NHAT :
A} 13/4 + 7/12 + 3/4 + 17/12
B} 1 VA 2/3 + 4 VA 4/7 + 5 VA 1/3 + 6 VA 3/7
C} 3/4 * 7/9 = 3/4 * 2/9
D} 3/4 * 4/5 * 5/6
BAI 3 : TINH
A} 3/4 CUA 16 KG .....
B} 7/12 CUA 840 M .....
C} 13/15 CUA 135 M3 .....
D} 6/7 CUA 280 L......
Thuc hien phep tinh bang cach tinh nhanh :
a) 4/9 + 3/2 + 6/36.
b) 2/7 x 5/17 + 12/7 x 15/17.
c) 2,34 + 5,18 + 7,66.
d) 7/11 : 3/4 + 7/11 : 1/4.
GIUP MINH MINH DANG CAN GAP.
tinh nhanh :D=2+3-4-5+6+7-8-9+10+....+2011-2012+2013+2014