1/6+1/66+1/176+....+1/496.501
=1/1.6+1/6.11+1/11.16+....+1/496.501
=(1/5).(5/1.6+5/6.11+5/11.16+....+5/496.501)
=(1/5).(1-1/6+1/6-1/11+1/11-1/16+...+1/496-1/501)
=(1/5).(1-1/501)
=1/5 . 500/501
=100/501
1/6+1/66+1/176+....+1/496.501
=1/1.6+1/6.11+1/11.16+....+1/496.501
=(1/5).(5/1.6+5/6.11+5/11.16+....+5/496.501)
=(1/5).(1-1/6+1/6-1/11+1/11-1/16+...+1/496-1/501)
=(1/5).(1-1/501)
=1/5 . 500/501
=100/501
Tìm X biết X+1/6+1/66+1/176+1/336+...+1/496×501 =1/501
Tính A= 1/20+1/30+1/42+1/56+...+1/990
Tính S= 1/6+1/66+1/176+1/336+...+1/496*501
So sánh A và B :
A=2016^2016+2/2016^2016-1 và B=2016^2016/2016^2016-3
Tính nhanh : B=1/6+1/66+1/176+1/336+...+1/496.501
Tinh nhanh:
B=1/6+1/66+1/176+1/336+.....+1/496.501
Tính nhanh : B=1/6 1/66 1/176 1/336 ... 1/10706
1/6+1/66+1/176+1/336+...+1/496.501
tính tổng :1/6+1/66+1/176+1/336+...+1/496.501
B= \(\frac{1}{6}+\frac{1}{66}+\frac{1}{176}+\frac{1}{336}+....+\frac{1}{496.501}\)
Tính tổng 100 số đầu tiên của dãy số sau: 1/6:1/66:1/176:1/336...