Question

112 timbre Mihai cu Elena, 89 timbre Elena cu Doru, 103 timbre Doru cu Mihai. Cate timbre au fiecare??

Answer 1

m+e=112
e+d=89
d+m=103
m=112-e
d=89-e
112+89-2e=103
2e=201-103
2e=98
e=49=>m=112-49=63=>d=40

Answer 2

Răspuns:

M=63, E=49, D=40

Explicație pas cu pas:

M+E=112

    E+D=89

M  +  D=103

M+E+E+D+M+D=112+89+103

2M+2E+2D=304

M+E+D=304:2

M+E+D=152

M+E=112

D=152-112

D=40

E+D=89

M=152-89

M=63

M+D=103

E=152-103

E=49