решите систему уравнений способом подставки {3 (x+4y) = 2 (2x+y) {7 (x-5y) + 6x=3 (x+4y) + 27

{3 (x + 4 y) = 2 (2 x + y);

{7 (x - 5 y) + 6 x = 3 (x + 4 y) + 27;

{3 x + 12 y = 4 x + 2 y;

(7 x - 35 y + 6 x = 3 x + 12 y + 27;

{ (3 x - 4 x) + (12 y - 2 y) = 0;

{ (7 x + 6 x - 3 x) - (35 y + 12 y) = 27;

{10 y - x = 0; x = 10 y;

{10 x - 47 y = 27;

10 * 10 y - 47 y = 27; 100 y - 47 y = 27; 53 y = 27;

y = 27/53;

x = 10 * 27/53; x = 270/53; x = 5 5/53;

{x = 5 5/53; y = 27/53.