Rozwiąż układ równań dla -x+3y+6=0 i 4x-3y-15=0

Rozwiązanie zadanego układu równań metodą podstawiania:

$\begin{cases}-x+3y+6=0 \\ 4x-3y-15=0 \end{cases}$

$3y-x=-6-3y+4x=15 $
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i: Ostateczne rozwiązanie to:

x = 3y + 6

  4•(3y+6) - 3y = 15
  9y = -9
  9y = - 9 

  y = - 1 
  x = 3y+6
  y = -1  x = 3(-1)+6 = 3 
 {x,y} = {3,-1}