Odpowiedzi

2009-09-14T15:41:31+02:00
I solanka

100% = 80 g
5 % = x

x = (80 * 5 )/ 100 = 400 / 100 = 4 g

80g + 20 g = 100g roztworu II

100% = 100 g
x = 4 g

x = (100 * 4) / 100 = 400 / 100 = 4 % -

stęrzenie 4 %
2009-09-14T16:20:19+02:00
80•5%+20•0%=(80+20)x% /•100
400+0=100x
420=100x
x=4