Răspuns :
1) 39-1-7-7=24- 3 p. egale
2)24:3=8- III nr.
3)8+7=15- II nr
4)15+1=16- I nr
a + b + c = 39
b = c + 1
a = b + 7
b + 7 + b + c = 39
c + 1 + 7 + c + 1 + c = 39
3c = 39 - 1 - 1 -7
3c = 39 - 9
3c = 30
c = 10
b = c + 1
b = 10 + 1
b = 11
a = b + 7
a = 11 + 7
a = 18
verificam
18 + 11 + 10 = 39
b = c + 1
a = b + 7
b + 7 + b + c = 39
c + 1 + 7 + c + 1 + c = 39
3c = 39 - 1 - 1 -7
3c = 39 - 9
3c = 30
c = 10
b = c + 1
b = 10 + 1
b = 11
a = b + 7
a = 11 + 7
a = 18
verificam
18 + 11 + 10 = 39