2. (10分) Let 0.a1a2a3a4 ...be the decimal expansion of the rational number
. Let bk = a2k,h = 1,2,...The decimal 0.b1b2b3b4... also represents a rational number
. Find
.
2. (10分) Let 0.a1a2a3a4 ...be the decimal expansion of the rational number
. Let bk = a2k,h = 1,2,...The decimal 0.b1b2b3b4... also represents a rational number
. Find
.