Răspunsuri

2014-02-12T18:11:23+02:00
4x+5y=17
5x+4y=15 |+
9x+9y=32 |:9
x+y=32/9  |*8
8x+8y=256/9

5x+4y=15
4x+5y=17 |-
x-y=-2        |*4
4x-4y=-8