Răspuns:
Explicație pas cu pas:
( 2/15 + 1/12 ) : 13/30 - 1/7 : 1/2 = 3/14
-> c.m.m.m.c al numitorilor 15 si 12 este = 3 × 4 × 5 = 60
-> amplific fractia 2/15 cu 4 = (2×4)/(15×4) = 8/60
-> amplific fractia 1/12 cu 5 = (1×5)/(12×5) = 5/60
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= ( 8/60 + 5/60) : 13/30 - (1/7) × 2 =
= (13/60) × 30/13 - 2/7 =
= (13/13) × (30/60) - 2/7 =
= 1/2 - 2/7
-> c.m.m.m.c al numitorilor 2 si 7 este 14
-> amplific fractia 1/2 cu 7 = 7/14
-> amplific fractia 2/7 cu 2 = (2×2)/(7×2) = 4/14
= 7/14 - 4/14 =
= 3/14
