Răspuns:
Explicație pas cu pas:
6 l lapte ...............1 kg smantana
9 l lapte ................x = 9/6 = 1,5 kg smantana
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1 kg smantana ......................6 l lapte
2 kg smantana ........................y = 2x 6 = 12 l lapte
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6 l lapte ...............1 kg smantana
15 l lapte ................z = 15/6 = 2,5 kg smantana
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1 kg smantana ......................6 l lapte
5 kg smantana ........................u = 5x 6 = 30 l lapte
