[(a+705·5)-1500·2]:5=160
[(a+3525)-3000]:5=160
(a+3525)-3000=160·5
(a+3525)-3000=800
a+3525=800+3000
a+3525=3800
a=3800-3525
a=275
[(a :7-30·10): 4+35]·9=945
(a :7-300): 4+35=945:9
(a :7-300): 4+35=105
(a :7-300): 4=105-35
(a :7-300): 4=70
a :7-300=70·4
a :7-300=280
a:7=280+300
a :7==580
a=580·7
a=4060
