Odpowiedź:
1) =312/125
2) 7/12
3) 27/10
312/100 × 4/5 = 312÷(25×5) = 312/125 = 2 62/125
7/3 × 1/4 = 7/12
7/5 + 1,3 = 14/10 + 13/10 = 27/10 = 2,7