Odpowiedzi

2009-09-07T17:25:29+02:00
A)x-y=2
½x-1=¼y

x=2+y
½*(2+y)=1/4y

x=2+y
1+1/2y=1/4y

x=2+y
1=1/4y-1/2y

x=2+y
1=1/4y-2/4y

x=2+y
1=-1/4y/*(-4)

x=2+y
y=-4

x=2-4
y=-4

x=-2
y=-4



B) x+2y=9
9-y=3x

X=9-2y
9-y=3x

x=9-2y
9-y=3*(9-2y)

x=9-2y
9-y=27-6y

x=9-2y
-y+6y=-9+27

x=9-2y
5y=18

x=9-2y
y=3,6

x=9-2*3,6
y=3,6

x=9-7,2
y=3,6

x=1,8
y=3,6