Question

tính bằng cách thuận tiện nhất B 1/2+1/4+1/8+1/16+1/32+1/64

Answer 1

1/2+1/4+1/8+1/16+1/32+1/64

=(1/2+1/4+1/8)+(1/16+1/32+1/64)

=(4/8+2/8+1/8)+(4/64+2/64+1/64)

=7/8+7/64

=56/64+7/64

=63/64

 

Answer 2

           B =        \(\dfrac{1}{2}\) + \(\dfrac{1}{4}\) + \(\dfrac{1}{8}\) +  \(\dfrac{1}{16}\)  + \(\dfrac{1}{32}\) + \(\dfrac{1}{64}\) 

    2 x B   = 1 + \(\dfrac{1}{2}\)+ \(\dfrac{1}{4}\)  +  \(\dfrac{1}{8}\) +  \(\dfrac{1}{16}\)+ \(\dfrac{1}{32}\)

2 x B - B = 1 - \(\dfrac{1}{64}\)

           B = \(\dfrac{63}{64}\)