2/1×3 + 2/3×5 + 2/5×7 + 2/7×9 + 2/9×11
= 1 - 1/3 + 1/3 - 1/5 + 1/5 - 1/7 + 1/7 - 1/9 + 1/9 - 1/11
= 1 - 1/11
= 10/11
Ủng hộ mk nha ♡_♡^_-
Đúng 0
Bình luận (0)
Các câu hỏi tương tự
Tính
a) 4/3*7 + 4/7*11 + 4/11*15 + 4/15*19 + 4/19*23 + 4/23*27
b) 1/2*3 + 1/3*4 + 1/4*5 + 1/5*6 +1/6*7
c) 2/3*5 + 2/5*7 + 2/7*9 + 2/9*11 + 2/11*13 + 2/1*2 + 2/2*3 + 2/3*4 + 2/8*9 + 2/9*10
2/1*3 +2/3*5+2/ 5*7+2/7*9+2/9*11
2/1 * 3 + 2/3 * 5 + 2/5 * 7 + 2/7 * 9 + 2/9 * 11
5/6 + 7/8
2+2/3
7/9 - 1/7
1-1/11
2 x 17/81
9/11 : 5/6
3:12/25
mong mn trả lời giúp ạ
Tính nhanh:
2/3 + 2/5 - 2/9 / 7/3 +7/5 - 7/9
+ 5/9 + 5/11- 5/13 / 7/9 + 7/11 - 7/13
7/9 + 2/3 - 5/18 =
11/5 - 3/4 + 7/15 =
7/8 + 5/9 : 2 =
4/15 : 2/3 + 5/7 =
A=2/3*5 + 2/5*7 + 2/7*9 + 2/9*11 + 2/11*13 + 2/11*15
B=2/1*2 + 2/2*3 + ..........+2/9*10
Giup mình theo kiểu bài như dưới đây nhé :
D =4/3*7 + 4/7*11 + 4/11*15 +............. + 4/23*27
D=7/3*7 - 3/3*7 + 11/7*11 + ................. + 23/23*27
D=1/3 -1/7 +1/7 - ................. - 1/27
D= 1/2 - 1/27
D= 8/27
a) ( ( -3/5 + 4/9 ) : 2/7 - (-14/9 + 2/5 ) :2/7 ) : (23/7 x 15/2 - 23/7 x 11/2)
b) ( 8 - 9/4 + 2/7) - (-6 x -3/7 + 5/4 ) - ( 3 + 2/4 - 9/7 )
Mình cảm ơn ! :v
a/2-3+5-7+9-11+13-15+17
b/1/1×2+1/2×3+1/3×4+1/4×5+1/5×6+1/6×7+1/7+8+1/8×9