[tex]a + b + c = 1500[/tex]
[tex]a + b = 978[/tex]
[tex]978 + c = 1500[/tex]
[tex]c = 1500 - 978......c = 522[/tex]
[tex]c = a - 19[/tex]
[tex]522 = a - 19[/tex]
[tex]a = - 522 - 19........a = - 541[/tex]
[tex]a = c + 19[/tex]
-541 = c + 19
c =541+19
c = 560
Sper ca te am ajutat !!!!