\(A=\frac{4}{1.5}+\frac{4}{5.9}+\frac{4}{9.13}+....+\frac{4}{101.105}\)
\(A=1-\frac{1}{5}+\frac{1}{5}-\frac{1}{9}+\frac{1}{9}-\frac{1}{13}+...+\frac{1}{101}-\frac{1}{105}\)
\(A=1-\frac{1}{105}=\frac{104}{105}\)
a) B = \(\frac{4}{1.3}+\frac{4}{3.5}+\frac{4}{5.7}+.......+\frac{4}{99.101}\)
b) C = \(\frac{5}{1.5}+\frac{5}{5.9}+\frac{5}{9.13}+......+\frac{5}{101.105}\)
7/1.5+7/5.9+7/9.13+...+7/101.105
\(C=\frac{5}{1.5}+\frac{5}{5.9}+\frac{5}{9.13}+...+\frac{5}{101.105}\)
tính tổng : A=1.5 + 5.9 + ....+97.101+101.105
B=1.2^2+2.3^2+3.4^2+....+99.100^2
C=1.2+3.4+5.6+7.8+...+99.100
D=1.2.3+2.3.4+...+98.99.100
\(\frac{3}{1.5}+\frac{3}{5.9}+\frac{3}{9.13}+....+\frac{3}{101.105}\)
chú thích: dấu " . " là dấu nhân
các bạn giúp mik nhé
Tính tổng:
C=\(\frac{3}{1.5}+\frac{3}{5.9}+\frac{3}{9.13}+...+\frac{3}{101.105}\)
D=\(\frac{4}{2.7}+\frac{4}{7.12}+\frac{4}{12.17}+...+\frac{4}{102.107}\)
E=\(\frac{5}{3.7}+\frac{5}{7.11}+\frac{5}{11.15}+...+\frac{5}{103.107}\)
F=\(\frac{6}{2.7}+\frac{6}{7.12}+\frac{6}{12.17}+...+\frac{6}{102.107}\)
S=4/1.5+4/5.9+...+4/2001.2005
M=4\1.5+4\5.9+4\.13+,.............+4\213.2017
Giúp mik vs ạ
Tính: 4/1.5+4/5.9+...+4/2001.2005
