Question

rezolvati in multimea numerelor reale metoda substitutiei de ecuatii
x+y=-2
2x-y=4

Answer 1

x=-2-y x=-2-y
=> =>
2x-y=4 2(-2-y)-y=4


x=-2-y x=-2-y
=> => =>
-4+2y-y=4 -4+y=4


x=-2-y x=-2-8
=> => =>
y=4+4 y=8


x=-10
=> S=(-10;8)
y=8