Odpowiedzi

2010-03-26T14:25:32+01:00
X+y=28,80
x+1/4x=y-1/4y

x=28,80-y
1,25x=0,75y

1,25(28,80-y)=0,75y
36-1,25y=0,75y
0,75y+1,25y=36
2y=36
y=18

x+18=28,8
x=28,8-18
x=10,8