а) (-2) * 1/4 - 1/2 = -2/4 - 1/2 = -1/2 - 1/2 = -1
б) -1/2 (2/3 - 2/5) = -1/2 (10/15 - 6/15) = -1/2 * 4/15 = -4/30 = -2/15
а) (-2) * 1/4 - 1/2 = -2/4 - 1/2 = -1/2 - 1/2 = -1
б) -1/2 (2/3 - 2/5) = -1/2 (10/15 - 6/15) = -1/2 * 4/15 = -4/30 = -2/15