1.Rezolvati prin metoda substitutiei urmatoarele sisteme de ecuatii:

Răspuns:
1.)
y=-13+3×
-×+5y=-9
-×+5(-13+3×)=-9
×=4
2.)
y=-11-6×
x+4y=-21
×+4(-11-6×)=-21
×=-1
y=-11-6×(-1)
y=-5
(×,y)=(-1,-5)