Answer: solanka 6-procentowa=3 kg
solanka 9-procentowa = 6 kg
Step-by-step explanation:
Let solanka 6-procentowa=x kg
Let solanka 9-procentowa = y kg
So x+y=9
=> x=9-y (1)
6%=0.06 9%=0.09 8%=0.08
So pure salt is 0.06*x +0.09*y= 9*0.08 (2)
Lets put 9-y instead x in (2)
0.06*(9-y) +0.09*y=0.72
0.54-0.06*y +0.09*y=0.72
0.03*y=0.18
y=6kg => x=9-y => x=9-6=3 kg