a) x + y = 9 / *(-1)
x - y = 3
-x - y = - 9
x - y = 3
-2y = -6/(-2)
y = 3
x - y = 3
x - 3 = 3
x = 3 +3
x = 6
x = 6
y = 3
b)3x + 2y = 2
3y = 12/ 3
y = 4
3x + 2y = 2
3x + 2*4 = 2
3x = 2 - 8
3x = -6/ 3
x = -2
x = -2
y = 4
c)3x + 2y = 5
2x + 2y = 2/ * (-1)
3x + 2y = 5
-2x - 2y = -2
x = 2
3x + 2y = 5
3*2 + 2y = 5
2y = 5 - 6
2 y = -1/2
y = -1
x = 2
y = -1
d) x + 4y = 11/ * (-2)
2x + 5y = 10
-2x -8y = -22
2x + 5y = 10
-3y = -12/ (-3)
y = 4
Dalej tak, jak wyżej.
e) -2x + 5y = 10/ * 4
7x - 4y = 8/ * 5
Dalej tak, jak wyżej.