Question

Rezolvati in multimea numerelor reale sistemul de ecuatie
x-y=0
5x+y=1

4x-y=0
8x-2y=3

2x+3y=1
2x-5y=9

Answer 1

1)
x=y
5x+x=1
6x=1
x=1/6 =y

2)
4x=y
8x-2*4x=3
8x-8x=3
0=3
x=y=Ф ( nu exista solutii)

3)
2x+3y-2x+5y=1-9
8y=-8
y=-8:8
y=-1
2x-3=1
2x=3+1
2x=4
x=2