\(M=\frac{2}{7.9}+\frac{2}{9.11}+\frac{2}{11.13}+\frac{2}{13.15}\)
\( M=\frac{9-7}{7.9}+\frac{11-9}{9.11}+\frac{13-11}{11.13}+\frac{15-13}{13.15}\)
\(M=\frac{9}{7.9}-\frac{7}{7.9}+\frac{11}{9.11}-\frac{9}{9.11}+\frac{13}{11.13}-\frac{11}{11.13}+\frac{15}{13.15}-\frac{13}{13.15}\)
\(M=\frac{1}{7}-\frac{1}{9}+\frac{1}{9}-\frac{1}{11}+\frac{1}{11}-\frac{1}{13}+\frac{1}{13}-\frac{1}{15}\)
\(M=\frac{1}{7}-\frac{1}{15}\)
\(M=\frac{15}{105}-\frac{7}{105}\)
\(M=\frac{8}{105}\)
Minh lam dung 100% do
TICK CHO MINH NHA!!!!!
\(M=\frac{2}{7\cdot9}+\frac{2}{9\cdot11}+\frac{2}{11\cdot13}+\frac{2}{12\cdot15}\)đề này sai bạn ạ mà toán nay là toán lớp 4 hả??