Răspuns :
(a+25)x3-100=17
(a+25)x3=100+17
(a+25)x3=117
a+25=117:3
a+25=39
a=39-25
a=14
proba:(14+25)x3-100=39x3-100=117-100=17
(a+25)x3=100+17
(a+25)x3=117
a+25=117:3
a+25=39
a=39-25
a=14
proba:(14+25)x3-100=39x3-100=117-100=17