Odpowiedź :
Zadanie 1 :
{-2x + 3y = 5 / * 3
{6x - 8y = 3
{-6x + 9y = 15
+ {6x - 8y = 3
---------------------
y = 18
-2x + 3 * 18 = 5
-2x + 54 = 5
-2x = 5 - 54
-2x = -49 / : (-2)
x = 24,5
Zadanie 2 :
{2x - y = 5
{3x + 5y = 27
{y = 2x - 5
{3x + 5(2x - 5) = 27
{y = 2x - 5
{3x + 10x - 25 = 27 / + 25
{y = 2x - 5
{13x = 52 / : 13
{x = 4
{y = 2 * 4 - 5
{x = 4
{y = 3