N=1/1.2+1/2.3+1/3.4+1/4.5+1/5.6+1/6.7
N=1-1/2+1/2-1/3+1/3-1/4+1/4-1/5+1/5-1/6+1/6-1/7
N=1-1/7=6/7
Ung ho mk nhe
Đúng 0
Bình luận (0)
Các câu hỏi tương tự
Tính
1. A= 1/2+1/6+1/12+/1/20+1/30+1/42+1/56
2. B = 3/2+5/6+7/12+-9/20+11/30-13/42+15/56
1/2 + 1/6 +1/12 +1/20 + 1/30 +1/42+ 1/56
17 tháng 4 2023 lúc 18:47
Tính nhanh
1/2 + 1/6 + 1/12 + 1/20 + 1/30 + 1/42
1/2+1/6+1/12+1/20+1/30+1/42
1/2+ 1/6 + 1/12+ 1/20+1/30+ 1/42 = ?
Tính: 1/2 + 1/6 + 1/12 + 1/20 + 1/30 + 1/42 + 1/56
Tính nhanh
1/2+1/6+1/12+1/20+1/30+1/42
1/90-1/72-1/56-1/42-1/30-1/20-1/12-1/6-1/2 = ?
8/9 - 1/72 - 1/56 - 1/42 - 1/30 - 1/20 - 1/12 - 1/6 - 1/2