Tinh nhanh: 8/9 X 15/16 X 24/25 X ... X 2499/2500
Tính: 8/9 x 15/16 x 24/25 x...x 2499/2500
8/9 x 15/16 x 24/25 x...x 2499/2500
= \(\frac{2\times4}{3\times3}\times\frac{3\times5}{4\times4}\times\frac{4\times6}{5\times5}\times...\times\frac{49\times51}{50\times50}\)
= \(\frac{2\times4\times3\times5\times4\times6\times...\times49\times51}{3\times3\times4\times4\times5\times5\times...\times50\times50}\)
= \(\frac{2\times51}{3\times50}\)
= \(\frac{17}{25}\)
\(\frac{8}{9}.\frac{15}{16}.\frac{24}{25}....\frac{2499}{2500}=\frac{8.15...2499}{9.16...2500}=\frac{2.4.3.5...49.51}{3.3.4.4...50.50}=\frac{\left(2.3.4...49.50\right).\left(4.5...49.51\right)}{\left(2.3.4...49.50\right).\left(3.4.5...49.50\right)}=\frac{51}{3.50}\)\(=\frac{17}{50}\)
tìm kết quả tích sau:
A= \(\dfrac{8}{9}\)x\(\dfrac{15}{16}\)x\(\dfrac{24}{25}\)x...x\(\dfrac{2499}{2500}\)
= 2x4/3x3 x 3x5/4x4 x 4x6/5x5 x.....x 49x51/50x50
= 2x4x3x5x4x6x...49x51/ 3x3x4x4x5x5...50x50
= 2x51/3x50
= 17/25
Tính nhanh.
8/9 x 15/16 x 24/25 x...x 2499/2500
/ là dấu gạch phân số
\(\frac{8}{9}\). \(\frac{15}{16}\). \(\frac{24}{25}\). ..... . \(\frac{2499}{2500}\)
= \(\frac{2.4}{3.3}\). \(\frac{3.5}{4.4}\). \(\frac{4.6}{5.5}\). .... . \(\frac{49.51}{50.50}\)
= \(\frac{2.4.3.5.4.6.49.51}{3.3.4.4.5.5.....50.50}\)= \(\frac{2.51}{3.50}\)= \(\frac{17}{25}\)
A =8/9 x 15/16 x 24/25 x.......x 2499/2500
B=( 1 -1/3) x (1-1/6)x (1- 1/10)x .....x ( 1- 1/780)
Tính nhanh nha các bạn ơi
Tính: 8/9 . 15/16 . 24/25 . ..... . 2499/2500
3^4*8^9*15^16*24^25*...2499^2500
CTR : 3/4 + 8/9 + 15/16 + 24/25 +....+ 2499/2500 > 48
* Giúp mình với :(
Rút gon: A= 8/9*15/16*24/25*...*2499/2500
giúp mk với nhé!
\(=\frac{2.4}{3^2}.\frac{3.5}{4^2}....\frac{49.51}{50^2}\)
\(=\frac{2.3....49}{3.4....50}.\frac{4.5....51}{3.4....50}\)
\(=\frac{2}{50}.\frac{17}{1}\)
\(=\frac{17}{25}\)
Ta có : \(A=\frac{8}{9}.\frac{15}{16}.....\frac{2499}{2500}\)
\(A=\frac{8.15.....2499}{9.16.....2500}\)
\(A=\frac{\left(2.4\right).\left(3.5\right).....\left(49.51\right)}{\left(3.3\right).\left(4.4\right).....\left(50.50\right)}\)
\(A=\frac{\left(2.3....49\right).\left(4.5....51\right)}{\left(3.4....50\right).\left(3.4.....50\right)}\)
\(A=\frac{2\left(3.4.....49\right).\left(4.5.....50\right).51}{\left(3.4.....49\right).50.3.\left(4.5.....50\right)}\)
\(A=\frac{2.51}{3.50}\)
\(A=\frac{2.17.3}{3.25.2}\)
\(A=\frac{17}{25}\)