bài 1 tính
Q=\(\frac{1}{2\times9}\)+\(\frac{1}{9\times7}\)+\(\frac{1}{7\times19}\)+..............+\(\frac{1}{252\times509}\)
R=\(\frac{1}{10\times9}\)+\(\frac{1}{18\times13}\)+\(\frac{1}{26\times17}\)+...........+\(\frac{1}{802\times405}\)
S=\(\frac{2}{4\times7}\)\(-\)\(\frac{3}{5\times9}\)+\(\frac{2}{7\times10}\)\(-\)\(\frac{3}{9\times13}\)+..................+\(\frac{2}{301\times304}\)\(-\)\(\frac{3}{401\times403}\)
ai nhanh nhất mik tick
Tìm số nguyên âm x, biết:
\(^{x^2}-\left(\frac{3}{5}\right)^2=\frac{1}{1\times2}+\frac{1}{2\times7}+\frac{1}{5\times7}+\frac{1}{5\times13}+\frac{1}{8\times13}+\frac{1}{8\times19}+\frac{1}{11\times19}+\frac{1}{11\times19}+\frac{1}{11\times25}\)
AI NHANH MK TICK CHO NHA!
\(\frac{1}{2\times3}+\frac{1}{3\times4}+\frac{1}{4\times5}+\frac{1}{5\times6}+\frac{1}{6\times7}+\frac{1}{7\times8}+\frac{1}{8\times9}+\frac{1}{9\times10}\)
Bài 9: Tìm x biết:
a, \(x+\frac{4}{5\times9}+\frac{4}{9\times13}+\frac{4}{13\times17}+....+\frac{4}{41\times45}=\frac{-37}{45}\)
b, \(x-\frac{20}{11\times13}-\frac{20}{13\times15}-\frac{20}{15\times17}-....-\frac{20}{53\times55}=\frac{3}{11}\)
c, \(\frac{1}{21}+\frac{1}{21}+\frac{1}{36}+.....+\frac{2}{x+\left(x+1\right)}=\frac{2}{9}\)
Giúp mình với!!!!!
Tính:
G=\(\frac{1}{1\times3\times5}+\frac{1}{5\times7\times9}+\frac{1}{9\times11\times13}+...+\frac{1}{49\times51\times53}\)
\(S=\frac{1}{5\times9}+\frac{1}{9\times13}+\frac{1}{13\times17}+\frac{1}{17\times21}+\frac{1}{21\times25}\)
Tính \(\frac{1}{6\times10}+\frac{1}{7\times9}+\frac{1}{8\times8}+\frac{1}{9\times7}+\frac{1}{10\times6}\)
Tính
a) \(M=\frac{2}{3\times5}+\frac{2}{5\times7}+\frac{2}{7\times9}+...+\frac{2}{97\times99}\)
b) \(N=\frac{3}{5\times7}+\frac{3}{7\times9}+\frac{3}{9\times11}+...+\frac{3}{197\times199}\)
Các bạn giúp mk nha! Cần lắm! Thanks các bạn nhiều
\(a=\frac{1}{3\times5}+\frac{1}{5\times7}+\frac{1}{7\times9}+......+\frac{1}{2003\times2005}\)
\(\frac{1}{3\times5}+\frac{1}{5\times7}+\frac{1}{7\times9}+...+\frac{1}{\left(2x+1\right)\left(2x+3\right)}=\frac{15}{96}\)
