👤
Mixa
a fost răspuns

Exercitiul 10 (B;C)

Exercitiul 10 BC class=

Răspuns :

b)[tex] \left \{ {{x+y=4} \atop {3x+y=6}} \right. [/tex] ⇒ [tex] \left \{ {{3x+3y=12} \atop {-3x-y=-6}} \right. [/tex] ⇒ 2y= 6 ⇒ y=3
x+y=4 ⇒ x+3=4⇒ x=1
c)[tex] \left \{ {{x-y=5} \atop {-x+3y=19}} \right. [/tex] ⇒ 2y=24 ⇒ y=12
x-y = 5⇒x-12=5⇒x=17