1) 3 1/4 +6,4 +7,5 = 13/4+6,4+7,5 = 3,25+6,4+7,5= 17,15
2) (21,3 - 18 3/4) : 3,4 = (21,3 - 75/4) : 3,4 = (21,3 - 18,75) : 3,4 = 2,55 : 3,4 = 0,75
3) 2/11 * (14 1/3 + 2 1/6) = 2/11 * ( 43/3 + 13/6) = 2/11 * ( 43*2 + 13 ) = 2/11 * 99/6
6
= 2/11 * 33/2 = 2*33 = 3
11*2
4) (5 1/6 - 3,25)* 4/23 = (31/6 - 3 1/4) * 4/23 = (31/6 - 13/4) * 4/23 =
= (31*2 - 13*3) * 4/23 = (62 - 39) * 4/23 = 23/12 * 4/23 = 23 * 4 = 1/3
12 12 12 * 23
5) 16,5 : 2,75 - 1/19*57 = 6 - 1*57 = 6 - 3 = 3
19
6) 2 1/7 : 5/6 * 7/9 - 1,9 = 15/7 : 5/6 * 7/9 - 1,9 = 15 * 6 * 7 - 1,9 = 2 - 1,9 = 0,1
7 * 5 * 9