Jeśli jest ktoś w stanie pomóc to był bym wdzięczny

Hej!
Zadanie 1 :
a)
{2x + y = -1
{x = y + 7
{x = y + 7
{2(y + 7) + y = -1
{x = y + 7
{2y + 14 + y = -1 / -14
{x = y + 7
{3y = -15 / : 3
{y = -5
{x = -5 + 7
{x = 2
{y = -5
b)
{2x - 5y = 2
{y - 2x = -10
{y = 2x - 10
{2x - 5(2x - 10) = 2
{y = 2x - 10
{2x - 10x + 50 = 2 / -50
{y = 2x - 10
{-8x = -48 / : (-8)
{x = 6
{y = 2 * 6 - 10
{x = 6
{y = 2
Zadanie 2 :
a)
{-2x + y = 4
+ {2x + 2y = 2
--------------------
3y = 6 / : 3
y = 2
-2x + 2 = -4 / -2
-2x = -6 / : (-2)
x = 3
b)
{-3x + 2y = -1 / * 3
{2x - 3y = 1 / * 2
{-9x + 6y = -3
+ {4x - 6y = 2
--------------------
-5x = -1 / : (-5)
x = 0,2
2 * 0,2 - 3y = 1
0,4 - 3y = 1 / -0,4
-3y = 0,6 / : (-3)
y = -0,2
Pozdrawiam! - Julka