Question

va rog ma poate ajuta cineva ?? vreau rezolvare completa​

Answer 1

Răspuns:

(x; y) = (1;-2)

a) $\left \{ {{x+y=3} \atop {-2x+y=-4}} \right.$   ⇒ $\left \{ {{1-2=3} \atop {-2*1-2=-4}} \right.$   ⇒ $\left \{ {{-1\neq 3 } \atop {-4=-4}} \right.$ ⇒ (x; y) ≠ (1;-2)

b) $\left \{ {{x-y=3} \atop {4x+y=2}} \right.$   ⇒  $\left \{ {{1+2=3} \atop {4*1-2=2}} \right.$  ⇒  $\left \{ {{3=3} \atop {2=2}} \right.$   ⇒ (x; y) = (1;-2)

c) $\left \{ {{2x-y=7} \atop {5x+3y=-1}} \right.$   ⇒  $\left \{ {{2*1+2=7} \atop {5*1-2*3=-1}} \right.$  ⇒  $\left \{ {{4=7} \atop {-1=-1}} \right.$   ⇒ (x; y) ≠ (1;-2)

c) $\left \{ {{4x-3y=10} \atop {-x+5y=-11}} \right.$   ⇒  $\left \{ {{4*1+2*3=10} \atop {-1-2*5=-11}} \right.$  ⇒  $\left \{ {{10=10} \atop {-11=-11}} \right.$   ⇒ (x; y) = (1;-2)

Explicație pas cu pas: