Răspuns :
Ex 1 : Notam nr cu a, b si c
a+b+c = 5413
b+c = 2978
=> a = 5413- 2978 => a= 2435
b = a - 1359 => b = 2435 - 1359 => b = 1076
=> c = 5413- 2435 - 1076 => c = 1902
1)
a+b+c=5413
b+c=2978
a=b+1359
rezolvare
a+2978=5413
a=5413-2978=2435
a=b+1359
2435=b+1359
2435-1359=b⇒b=1076
b+c=2978
1076+c=2978
c=2978-1076=1902
soltii
a=2435
b=1076
c=1902
verificare
2435+1076+1902=5413
3511+1902=5413
5413=5413
1076+1902=2978
2978=2978
2435=1076+1359
2435=2435
2)
d+r+a=5565
d+r=3581
r+a=3829
rezolvare
3581+a=5565
a=5565-3581=1984
r+a=3829
r+1984=3829
r=3829-1984=1845
d+r=3581
d+1845=3581
d=3581-1845=1736
solutii
a=1984
d=1736
r=1845
verificare
1736+1845+1984=5565
3581+1984=5565
5565=5565
1736+1845=3581
3581=3581
1845+1984=3829
3829=3829
a+b+c=5413
b+c=2978
a=b+1359
rezolvare
a+2978=5413
a=5413-2978=2435
a=b+1359
2435=b+1359
2435-1359=b⇒b=1076
b+c=2978
1076+c=2978
c=2978-1076=1902
soltii
a=2435
b=1076
c=1902
verificare
2435+1076+1902=5413
3511+1902=5413
5413=5413
1076+1902=2978
2978=2978
2435=1076+1359
2435=2435
2)
d+r+a=5565
d+r=3581
r+a=3829
rezolvare
3581+a=5565
a=5565-3581=1984
r+a=3829
r+1984=3829
r=3829-1984=1845
d+r=3581
d+1845=3581
d=3581-1845=1736
solutii
a=1984
d=1736
r=1845
verificare
1736+1845+1984=5565
3581+1984=5565
5565=5565
1736+1845=3581
3581=3581
1845+1984=3829
3829=3829