Question

VA ROG URGENT!!!!!!!!​

Answer 1

Sper sa intelegi, daca nu, sa ma intrebi)

Answer 2

$\it b)\ \ -x+y=4 \Rightarrow y=4+x\ \ \ \ \ (*)\ (rela\c{\it t}ie\ de\ substitu\c{\it t}ie)\\ \\ 5x+2y=8\ \stackrel{(*)}{\Longrightarrow}5x+2\cdot(4+x)=8 \Rightarrow 5x+8=2x=8|_{-8} \Rightarrow7x=0 \Rightarrow x=0\\ \\ x=0\ \stackrel{(*)}{\Longrightarrow}\ y=4+0 \Rightarrow y=4\\ \\ Perechea\ (0,\ \ 4)\ este\ solu\c{\it t}ia\ sistemului$