\(\frac{5^2}{1.6}+\frac{5^2}{6.11}+\frac{5^2}{11.16}+\frac{5^2}{16.21}+\frac{5^2}{21.26}+\frac{5^2}{26.31}\)
Tính tổng trên bằng cách hợp lí
A= 15/1.6+15/6.11 +15/11.16 +15/16.21 +15/21.26+ 15/26.31+15/31.36
CMR; A>2
E=5^2/1.6+5^2/6.11+5^2/11.16+5^2/16.21+5^2/21.26+5^2/26.31
. là nhân
Tính:
52/1.6 + 52/ 6.11 + 52/11.16 + 52/16.21 + 52/21.26 + 52/26.31
\(\frac{5^2}{1.6}+\frac{5^2}{6.11}+\frac{5^2}{11.16}+\frac{5^2}{16.21}+\frac{5^2}{21.26}+\frac{5^2}{26.31}\)
\(\frac{5^2}{1.6}+\frac{5^2}{6.11}+\frac{5^2}{11.16}+\frac{5^2}{16.21}+\frac{5^2}{21.26}+\frac{5^2}{26.31}\) =?
Tinh
\(\frac{5^2}{1.6}+\frac{5^2}{6.11}+\frac{5^2}{11.16}+\frac{5^2}{16.21}+\frac{5^2}{21.26}+\frac{5^2}{26.31}\)
Tính hợp lí tổng sau:
52/ 1.6 + 52/ 6.11 + 52/ 11.6 + 52/ 16.21 + 52/ 21.26 + 52/ 26.31
A, m= 4/1.3+4/3.5+4/5.7+....+4/2013.2015
b,S=2/5.9+2/9.13+2/13.17+....+2/97.101
c,A=1/5.6+1/6.7+1/7.8+......+1/24.25
d,B=2/1.3+2/3.5+2/5.7+....+2/99.101
e,C=52/1.6+52/6.11+52/11.16+52/16.21+52/21.26+52/26.31
Tính:
M=1/2+1/6+1/12+1/20+1/30+1/42
N=52/1.6+52/11.16+52/16.21+52/21.26+52/26.31