12 × (13/24 - 7/12) = 12 × (13/24 - (7/12)×2)) = 12× (13/24 - 14/24) = 12 × ( 13 - 14/24) = 12 × (- 1/24)= - 1 × 12 / 24 = -12 / 24= - 1/2 = - 0,5
12 × (13/24 - 7/12) = 12 × (13/24 - (7/12)×2)) = 12× (13/24 - 14/24) = 12 × ( 13 - 14/24) = 12 × (- 1/24)= - 1 × 12 / 24 = -12 / 24= - 1/2 = - 0,5