Giải thích các bước giải:
# come on in vietnam
# rincoolbodoi
∵
∴
$\frac{1}{20}$ + $\frac{1}{44}$ + $\frac{1}{77}$ + $\frac{1}{115}$ + $\frac{1}{176}$
=( $\frac{1}{20}$ + $\frac{1}{155}$ ) + ($\frac{1}{144}$ + $\frac{1}{176}$ )+ $\frac{1}{77}$
=( $\frac{23}{460}$ + $\frac{4}{115}$ ) + ($\frac{4}{176}$ + $\frac{1}{176}$ ) + $\frac{1}{77}$
=$\frac{27}{460}$ + $\frac{5}{176}$ +$\frac{1}{77}$
=$\frac{84316}{141680}$ + $\frac{4025}{141680}$ +$\frac{1840}{141680}$
=$\frac{14181}{141680}$
$\frac{RINDAUBUI}$
