1分之21+202分之2121+50505分之212121+13131313分之21212121

问题描述:

1分之21+202分之2121+50505分之212121+13131313分之21212121

21/1 + 2121/202 + 212121/50505 + 21212121/13131313= 21 ×( 1/1 + 101/202 + 10101/50505 + 1010101/13131313 )= 21 ×( 1 + 1/2 + 1/5 + 1/13 )= 21 ×(130+65+26+10)/130= 21 × 231/130= 1851/130=