a) $129-5.[29-(6-1)^2]$
$=129-5.[29-5^2]$
$=129-5.4$
$=129-20=109$
b) $500-5.[409-(2^3.3-21)^2+10^3] : 15 $
$=500-5.[409-(24-21)^2+10^3] : 15$
$=500-5.[400+1000] :15$
$=500-5.1040: 15 $
$=500- \frac{1040}{3}$
$=\frac{460}{3}$
c) $59.73-30^2+27.59$
$=59.(73+27) - 900$
$=59.100-900$
$=5900-900=5000$
Chúc bạn học tốt !