In general numerele pare sunt de forma 2k, unde k e numar natural. Diferenta dintre doua numere pare consecutive e 2.
Notezi a=2k, b=a+2=2k+2, c=b+2=(2k+2)+2=2k+4, d=c+2=(2k+4)+2=2k+6
Stii a+d=558 si inlocuiesti cu notatiile de mai sus.
2k + 2k+6 = 558
4k = 558-6
4k= 552
k= 552/4
k= 113
Deci a = 2*113= 226, b=2*113+2=226+2=228, c=2*113+4=226+4=230, d=2*113+6=226+6=232
Suma celor 4 numere este: a+b+c+d= 226+228+230+232= 516
