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Puritatea substantelor masa substantelor impure =500g, masa substantelor pure=x, masa impuritatilor=y, puritatea substantelor=80%​

Răspuns :

Răspuns:

80/100=masa pura/500

80/100=x/500

X=80*500/100

X=80*5

X=400g

500=400+y

Y=500-400

Y=100g