Odpowiedzi

2010-01-05T16:46:48+01:00

a)
2x+9y=-9 /*3
-3x+3y=8 /*2

6x+27y=-27
-6x+6y= 16
___________
33y=-11 /:33
y=-⅓

2x+9y=-9
2x+9*(-⅓)=-9
2x-3=-9
2x=-9+3
2x=-6 /:2
x=-3

y=-⅓
x=-3


b)
2x+3y=4 /*8
8x-5y=-1 /*(-2)

16x+24y=32
-16x+10y=2
________________
34y=34 /:34
y=1

2x+3y=4
2x+3*1=4
2x=4-3
2x=1 /:2
x=½