(1/6 + 2/3) * 3 = (1/6 + 4/6) * 3 = 5/6 * 3 = 5/2 = 2,5
(1/8 + 3/4) : 5 = (1/8 + 6/8) : 5 = 7/8 : 5 = 7/40
(1/2 + 1/3) * 2= (3/6 + 2/6) * 2 = 5/6 * 2 =5/3 = 1ц.2/3
(17/30 - 2/15) : 13 = (17/30 - 4/30) : 13 = 13/30 : 13 = 1/30
(4/3 + 1/9) * 4 = (12/9 + 1/9) * 4 = 13/9 * 4 = 52/9 = 5ц 7/9
(1/2 - 1/3) * 3 = (3/6 - 2/6) * 3 = 1/6 * 3 = 1/2 = 0,5