Rozwiąż układ równań dla 4x+2y=6 i 9x-7y+25

Rozwiązanie zadanego układu równań metodą podstawiania:

$\begin{cases}4x+2y=6 \\ 9x-7y+25 \end{cases}$

$2y+4x=6-7y+9x=-25 $
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i: Ostateczne rozwiązanie to:

9x = 7y - 25

x = 7y/9 - 25/9
  4•(7y/9-25/9) + 2y = 6
  46y/9 = 154/9
  46y = 154
  46y = 154 

  y = 77/23 
  x = 7y/9-25/9
  y = 77/23  x = (7/9)(77/23)-25/9 = -4/23 
 {x,y} = {-4/23,77/23}