Question

Tính tích :

     ( 1 + 7/9 ) . ( 1 + 7/20 ) . ( 1 + 7/33 ) ........ ( 1 + 7/2900 ) 

Answer 1

(1+7/9)x(1+7/20)x(1+7/33)x...x(1+7/2900)

=(8x2)/(9x1) x (9x3)/(10x2) x 10x4/(11x3) x ...x(57x51)/(58x50)

=(8x2x9x3x10x4x...x57x51)x(9x1x10x2x11x3x...x58x50)

Sau khi giản ước ta được:

(8x51)/(1x58)=204/29

mk ko chắc chắn lắm đâu

Answer 2

( 1 + 7/9 ) . ( 1 × 7/20 ) . ( 1 + 7/33 ) ... ( 1 + 7/2900 )

= 16/9 . 27/20 . 40/33 ... 2907/2900

= 2.8/1.9 . 3.9/2.10 . 4.10/3.11 ... 51.57/50.58

= 2.3.4...51/1.2.3...50 . 8.9.10...57/9.10.11...58

= 51 . 8/58

= 204/29