B =1/3 + 1/6 + 1/10 + 1/15 + 1/21 + 1/28
B = 1 - 1/3 + 1/3 - 1/6 + 1/6 - 1/10 + 1/10 - 1/15 + 1/15 - 1/21 + 1/21 - 1/28
B = 1 - ( 1/3 + 1/3 - 1/6 + 1/6 - 1/10 + 1/10 - 1/15 + 1/15 - 1/21 + 1/21 ) - 1/28
B = 1 - 1/28
B = 27/28
~ Hok T ~
Các câu hỏi tương tự
tính nhanh
1+1/3+1/6+1/10+1/15+1/21+1/28+1/36
TÍNH 1+1/3+1/6+1/10+1/15+1/21+1/28+1/36+1/45+1/55+1/66
C = 1/3 + 1/6 + 1/10 + 1/15 + 1/21 + 1/28
A=1+1/3+1/6+1/10+1/15+1/21+1/28+1/36+1/45
Giúp tớ giải nốt 2 bài tính nhanh này nhé, thanks
B = 1/3 + 1/6 + 1/10 + 1/15 + 1/21 + 1/28
D = 2009 x 2010 + 2000 / 2011 x 2010 - 2020
1/3+1/6+1/10+1/15+1/21+1/28+1/36+1/45
A= 1/3 + 1/6 + 1/10 + 1/15 + 1/21 +1/28 + 1/36 +1/45 + 1/55
tinh nhanh
A = 1/3 + 1/6 + 1/10 + 1/15 + 1/21 + 1/28
Tính nhanh giá trị biểu thức: M = 1/3+1/6+1/10+1/15+1/21+1/28+1/36+1/45