Question

Rezolvati in multimea numerelor deale sistemul de ecuatii:
$\left \{ {{2x-y=1} \atop {x+y=-4}} \right.$

Answer 1

rezulta 2x+x+y-y=1-4
3x=-3
x=-3/3
x=-1

din x+y=-4
rezulta -1+y=-4
y=-4+1
y=-3