Răspuns :
sistem: a+b=15 a=15-b a=15-6
a*b=56 <=> sist. (15-b)b=56 <=> sist. 15b-bpatrat=56 <=>
sist <=> a=15-b
bpatrat-15b+56=0 r: daca b=8, atunci a =7
daca b=7, atunci a =8
delta =1; b1=8
b2=7
a*b=56 <=> sist. (15-b)b=56 <=> sist. 15b-bpatrat=56 <=>
sist <=> a=15-b
bpatrat-15b+56=0 r: daca b=8, atunci a =7
daca b=7, atunci a =8
delta =1; b1=8
b2=7