Răspuns :
2x+4y=20
y-6=10⇒y=10+6=16
2x+4y=20
2x+4*16=20
2x+64=20
2x=20-64
2x=-44
x=-44÷2
x=-22
y-6=10⇒y=10+6=16
2x+4y=20
2x+4*16=20
2x+64=20
2x=20-64
2x=-44
x=-44÷2
x=-22
Daca y-6=10 atunci y = 16 ...De aici inlocuiesti in prima relatie :2x+4X16 = 20 ...De unde rezulta ca 2x=-44 , deci x= - 22 .... Inmultesti totul cu - 1 si o sa-ti dea ca -x=22