( 63+104+c ) : 3 = 75

Răspuns :

(63+104+c):3=75
(167+c):3=75
167+c=75x3=225
c=225-167=58
(63+104+c):3=75
(167+c):3=75. |•3
167+c=75•3
167+c=225. |-167
c=225-167
c=58
Succes!