A = 4/3 - 4/5 + 4/5 - 4/7 + ... + 4/27 - 4/29
A = 4/3 - 4/29
A = 104/87
A:8=1/3.5+1/5.7+...+1/27.29
A:8=1/3-1/5+1/5-1/7+...+1/27_1/29
A:8=1/3-1/29
A:8=26/27
A=208/87
\(\frac{8}{3.5}+\frac{8}{5.7}+....+\frac{8}{27.29}\)
\(=\frac{4}{3}-\frac{4}{5}+\frac{4}{5}-....+\frac{4}{27}+\frac{4}{29}\)
\(=\frac{4}{3}-\frac{4}{29}\)
\(=\frac{104}{87}\)
Ta có :
\(A=\frac{8}{3.5}+\frac{8}{5.7}+..+\frac{8}{27.29}\)
\(A=4\left(\frac{2}{3.5}+\frac{2}{5.7}+...+\frac{2}{27.29}\right)\)
\(A=4\left(\frac{1}{3}-\frac{1}{5}+\frac{1}{5}-\frac{1}{7}+...+\frac{1}{27}-\frac{1}{29}\right)\)
\(A=4\left(\frac{1}{3}-\frac{1}{29}\right)\)
\(A=4.\frac{26}{87}\)
\(A=\frac{104}{87}\)
Ủng hộ mk nha !!! ^_^
