Question

rezolvati astea va rog! dau coronita​

Answer 1

Răspuns:

Explicație pas cu pas:

Answer 2

$\it 1.\ a)\ 2x+y=28\ \Rightarrow\ y=28-2x\ \ \ \ \ (*)\\ \\ -x+y=1\stackrel{(*)}{\Longrightarrow} -x+28-2x=1\ \Rightarrow -3x=-27|_{:{(-3)}} \Rightarrow\ x=9\\ \\ x=9\stackrel{(*)}{\Longrightarrow}\ y=28-2\cdot9=28-18=10\\ \\ S=\{(9,\ \ 10)\}$

$\it b)\ \ \dfrac{x}{2}-\dfrac{2x+1}{3}=3-x|_{\cdot6}\ \Rightarrow\ 3x-4x-2=18-6x\ \Rightarrow\ 5x=20\ \Rightarrow\ x=4$