\(=2\left(\dfrac{2}{3.5}+\dfrac{2}{5.7}+...+\dfrac{2}{17.19}\right)\)
\(=2\left(\dfrac{1}{3}-\dfrac{1}{5}+\dfrac{1}{5}-\dfrac{1}{7}+...+\dfrac{1}{17}-\dfrac{1}{19}\right)\)
\(=2\left(\dfrac{1}{3}-\dfrac{1}{19}\right)=2\text{ }\times\dfrac{16}{57}=\dfrac{32}{57}\).
4/15+4/35+...+4/195+4/323
4/15+4/35+.....+4/195+4/323
\(\dfrac{4}{15}\)+\(\dfrac{4}{35}\)+.....+\(\dfrac{4}{195}\)+\(\dfrac{4}{323}\)
B = 1/4 + 1/15 + 1/35 + 1/63 + 1/99 + 1/143 + 1/195
2/35+4/77+2/143+4/221+2/323+4/437+2/575 = ?
J=2/35+4/77+2/143+4/221+2/323+4/437+2/575
tính giá trị biểu thức ;2/35+4/77+2/143+4/221+2/323+4/437+2/575
cho A va B biet:
\(A=\frac{2^{19}\cdot27^3+15\cdot4^9\cdot9^4}{6^9\cdot2^{10}+12^{10}}\) va \(B=\frac{4}{35}+\frac{4}{63}+\frac{4}{99}+\frac{4}{143}+\frac{4}{195}\)
2/35+ 4/77+ 2/143+ 4/221+ 2/323+ 4/437+ 2/575
Giải hộ tui bài này tôi like cho
