\(\frac{1.3.5.....49}{26.27.28....50}=\frac{\left(1.3.5...49\right).\left(2.4.6...48\right)}{\left(26.27.28...50\right).\left(2.4.6...48\right)}\)

                              \(=\frac{\left(1.2.3...25\right).\left(26.27.28...49\right)}{\left(26.27.28...50\right)\left(2.4.6...48\right)}\)

                              \(=\frac{1.2.3...25}{50.2.\left(1.2.3...24\right)}\)

                             \(=\frac{25}{50.2}=\frac{25}{100}=\frac{1}{4}\)

Học tốt!

Có ai giúp mình được không ?

chiuz

1/50331648

1/33554432

quy luat la gi

 the

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

chịu

chịu

chịu

\(\text{Ta có:}\)

\(B=\frac{1.3.5.....49}{26.27.....50}=\frac{1.2.3.....50}{26.27...50}.\frac{1}{2.4.....50}=\frac{1.2.3....25}{1.2.3....25.2^{25}}=\frac{1}{2^{25}}\)

bạn viết tất cả các số giống nhau giữa tử và mẫu ra rồi còn bao nhiêu bạn rút gọn

\(\frac{1.3.5....49}{27.28.29...50}=\frac{1.3.5....\left(27.29...49\right)}{\left(27.29...49\right).\left(28.30...50\right)}=\frac{1.3.5....25}{28.30....50}\)=\(\frac{13}{4^32^6.8.16.32}=\frac{13}{2^6.2^6.2^3.2^4.2^5}=\frac{13}{2^{24}}\)

Xét tử : \(1.3.5.....99\)

\(=\frac{1.2.3.4.....98.99.100}{2.4.6.....100}\) 

\(=\frac{\left(1.2.3.....50\right)\left(51.52.....99.100\right)}{\left(1.2\right).\left(2.2\right).....\left(50.2\right)}\)

\(=\frac{\left(1.2.3.....50.\right).\left(51.52.....100\right)}{\left(1.2.3.....50\right).2.2.....2}\)

\(=\frac{51.52.....100}{2.2....2}\)

\(=\frac{51}{2}.\frac{52}{2}.....\frac{100}{2}\)

Ta được phân số\(\frac{\frac{51}{2}.\frac{52}{2}.....\frac{100}{2}}{51.52.....100}\)

\(=\frac{\frac{51}{2}.\frac{52}{2}.....\frac{100}{2}}{\frac{51}{2}.\frac{52}{2}.....\frac{100}{2}.2.2.....2}\)

\(=\frac{1}{2.2.....2}\)

\(=\frac{1}{2^{50}}\)

hết cỡ rồi ông tướng

a, - 151515 / 232323 = -15/23

b, 1.2.3 + 2.4.6 + 4.8.12 / 1.3.5 + 2.4.6 + 4.12.20 

= 146/341