-(5/16 - 5/6) - (3/16 - 1/6) =
= -5/16+5/6-3/16+1/6 =
= (-5/16-3/16) + (5/6+1/6) =
= -8/16 - 1 = -1/2 -1 = -0,5 - 1 = -1,5
(3/4 - 2/15) - (1/15 + 1/4) =
= 3/4-2/15-1/15-1/4 =
= (3/4-1/4) + (-2/15-1/15) =
= 2/4 - 3/15 = 1/2 - 1/5 =
=0,5 - 0,2 = 0,3
-(3/8 - 5/7) + (7/8 - 5/7) =
= -3/8 + 5/7 +7/8 - 5/7 =
= (-3/8+7/8) + 5/7-5/7 =
= 4/8 = 1/2 = 0,5