Răspuns :
(58*a-80):25=1280:64
(58*a-80):25=20
58*a-80=25*20=500
58*a=500+80
58*a=580
a=580:58
a=10
(58*a-80):25=20
58*a-80=25*20=500
58*a=500+80
58*a=580
a=580:58
a=10