Question

(1+1:91)x(1+1:92)x(1+1:93)x...x(1+1:647)=???

giúp mk nha các bạn.

cám ơn trước.

Answer 1

\(B=\left(1+\frac{1}{91}\right).\left(1+\frac{1}{92}\right).\left(1+\frac{1}{93}\right).....\left(1+\frac{1}{647}\right)\)

\(B=\frac{92}{91}.\frac{93}{92}.\frac{94}{93}.....\frac{648}{647}\)

\(B=\frac{92.93.94....648}{91.92.93....647}\)

\(B=\frac{648}{91}\)

Answer 2

= 92/91x93/92x94/93x...x647/646

=92x93x94x...647 / 91x92x93x...x646

giản ước ta đc : 

= 647/91