Odpowiedzi

2009-12-07T15:57:03+01:00
90%-60%=30%
30%=15kg
90%=x
x=90%*15kg :30%
x= 45kg
2009-12-07T15:58:04+01:00
60%- x-15
90%- x

60x=90(x-15)
60x=90x-1350
-30x=-1350
x=45