Răspuns :
a+b+c=83
a-12.5=x
b-15.5=x
c-17.5=x
x+12.5+x+17.5+x+15.5=83
3*x=83-45.5
3*x=37.5
x=12.5
a=12.5+12.5=25
b=12.5+15.5=28
c=12.5+17.5=30
a-12.5=x
b-15.5=x
c-17.5=x
x+12.5+x+17.5+x+15.5=83
3*x=83-45.5
3*x=37.5
x=12.5
a=12.5+12.5=25
b=12.5+15.5=28
c=12.5+17.5=30
A + M + C = = 83 lei
A - 12,5 = M - 15,5 = C - 17,5
M = A +15,5-12,5
M = A + 3
C = A + 17,5 - 12,5
C = A + 5
inlocuim in prima ecuatie in functie de a
A + A + 3 + A + 5 = 83
3×A = 83 - 8
3×A = 75 |:3
A = 25
M = 25 + 3 = 28
C = 25 + 5 = 30
Verificare:
25+28+30 = 83
25 lei Ana
28 lei Maria
30 lei Carmen
A - 12,5 = M - 15,5 = C - 17,5
M = A +15,5-12,5
M = A + 3
C = A + 17,5 - 12,5
C = A + 5
inlocuim in prima ecuatie in functie de a
A + A + 3 + A + 5 = 83
3×A = 83 - 8
3×A = 75 |:3
A = 25
M = 25 + 3 = 28
C = 25 + 5 = 30
Verificare:
25+28+30 = 83
25 lei Ana
28 lei Maria
30 lei Carmen