\(\dfrac{7}{-9}+\dfrac{11}{9}=\dfrac{-7}{9}+\dfrac{11}{9}=\dfrac{4}{9}\)
\(\dfrac{7}{-9}+\dfrac{11}{9}=\dfrac{-7}{9}+\dfrac{11}{9}=\dfrac{4}{9}\)
1/3-3/5+5/7-7/9+9/11-11/13+13/15+11/13-9/11+7/9-5/7+3/5-1/3
tính nhanh: 1/3-3/5+5/7-7/9+9/11-11/13+13/15+11/13-9/11+7/9-5/7+3/5-1/3
tính nhanh: (4/5-4/11+4/13)/(9/5-9/11+9/13)+(5/7+5/11-5/13)/(9/7+9/11-9/13)
Tính
1/3 - 3/5 + 5/7 - 7/9 + 9/11 - 11/13 - 9/11 + 7/9 - 5/7 + 3/5 - 1/3
3+3/7-3/11+3/1001-3/13/9/1001-9/13+9/7-9/11+9
tính nhanh
-7/9 . 4/11 + -7/9 . 7/11 + 5 7/9
-7/9 . 3/11 + -7/9 . 8/11 + 1 7/9
giúp vs
Bài 3: Tính nhanh:
a) \(15\dfrac{3}{13}\)-\(\left(3\dfrac{4}{7}+8\dfrac{3}{13}\right)\)
b) \(\left(7\dfrac{4}{9}+4\dfrac{7}{11}\right)\)-\(3\dfrac{4}{9}\)
c) \(\dfrac{-7}{9}\).\(\dfrac{4}{11}\)+\(\dfrac{-7}{9}\).\(\dfrac{7}{11}\)+\(5\dfrac{7}{9}\)
d) 50%.\(1\dfrac{1}{3}\).10.\(\dfrac{7}{35}\).0,75
e) \(\dfrac{3}{1.4}\)+\(\dfrac{3}{4.7}\)+\(\dfrac{3}{7.10}\)+...+\(\dfrac{3}{40.43}\)
tính B=(3.4.216)2/11.213.411-169.3+3/7=3/11/9/7-9/11+9
tính hợp lí: -7/9 . 4/11 + -7/9 . 7/11 + 5 7/9
giúp vs mn ơi