[(58•a-80):25]=1280:64
[(58•a-80):25]=20
(58•a-80)=25•20
(58•a-80)=500
58•a=500+80
58•a=580
a=580:58
a=10
[(a+54)×4+6]×4=800+184
[(a+54)×4+6]×4=984
[(a+54)×4+6]=984:4
[(a+54)×4+6]=246
(a+54)×4=246-6
(a+54)×4=240
(a+54)=240:4
(a+54)=60
a+54=60
a=60-54
a=6
