\(A=1\cdot3\cdot5\cdot7\cdot\ldots\cdot49\)

\(=\frac{1\cdot2\cdot3\cdot\ldots\cdot50}{2\cdot4\cdot6\cdot\ldots\cdot50}\)

\(=\frac{1\cdot2\cdot3\cdot\ldots\cdot50}{2\cdot1\cdot2\cdot2\cdot2\cdot3\cdot\ldots\cdot2\cdot25}=\frac{1\cdot2\cdot3\cdot\ldots\cdot50}{2^{25}\cdot\left(1\cdot2\cdot3\cdot\ldots\cdot25\right)}\)

\(=\frac{26\cdot27\cdot\ldots\cdot50}{2^{25}}=\frac{26}{2}\cdot\frac{27}{2}\cdot\ldots\cdot\frac{50}{2}\)

quy luat la gi

 the

Rút gọn phân số sau: \(\frac{1.3.5.7...49}{26.27.28.29...50}\)

chịu

chịu

chịu

=(1.2.3....25)(25.26.27...49)\26.27.28....50.=1.2.3....25\50=1.2.3...12

Rút gọn phân số

$\frac{\mathrm{1.3.5.7...49}}{\mathrm{26.27.....50}}$

=$\frac{\left(\mathrm{1.2.3....25}\right).\left(\mathrm{25.26.27...49}\right)}{\mathrm{26.27.28....50}}$=$\frac{\mathrm{1.2.3....25}}{50}$=$\mathrm{1.2.3...12}$

k di mk giai cho cai nay ma ko g dc nua

mình ko biết làm

tứ 26 đến 48 bỏ hết vậy là xong

=\(\dfrac{\left(1.2.3....25\right).\left(25.26.27...49\right)}{26.27.28....50}\)=\(\dfrac{1.2.3....25}{50}\)=\(1.2.3...12\)

\(\frac{10.11+50.55+70.77}{11.12+55.60+77.84}=\frac{10.11.\left(1+5.5+7.7\right)}{11.12.\left(1+5.5+7.7\right)}=\frac{10}{12}=\frac{5}{6}\)