Răspuns :
d - 12 = 29
d = 12 + 29
d = 41
c + d = 70
c + 41 = 70
c = 70 - 41
c = 29
b + c = 67
b + 29 = 67
b = 67 - 29
b = 38
b - a = 13
38 - a = 13
a = 38 - 13
a = 25
Deci : a = 25, b = 38, c = 29, d = 41
d = 12 + 29
d = 41
c + d = 70
c + 41 = 70
c = 70 - 41
c = 29
b + c = 67
b + 29 = 67
b = 67 - 29
b = 38
b - a = 13
38 - a = 13
a = 38 - 13
a = 25
Deci : a = 25, b = 38, c = 29, d = 41