1) ( 6/5 - 3/4 ) × 2/3 = 9/20 × 2/3 = 3/10 ;
2) ( 6/5 - 2/3 ) × 1/2 = 8/15 × 1/2 = 4/15 ;
3) 11/18 - 4/9 × 3/16 = 11/18 - 1/12 = 19/36 ;
4) 29/30 - 5/18 × 6/25 = 29/30 - 1/15 = 9/10 ;
5) 8/5 × ( 3/4 + 11/8 ) = 8/5 × 2 1/8 = 3 2/5 ;
6) 18/7 × ( 4/9 + 15/8 ) = 18/7 × 2 23/72 =
2 27/28 ;
7) 8/5 × 3/4 + 11/8 = 1 1/5 + 11/8 = 2 23/40 ;
8) - 1/3 × 6/5 - 5/6 × 3/25 = ( - 2/5 ) - 1/10 =
( - 1/2 ) ;
9) 18/7 × 4/9 + 15/14 = 8/7 + 15/4 = 1 129/238 ;
10) - 1/4 × 8/6 - 7/18 × 9/21 = ( - 1/3 ) - 1/6 =
( - 1/2 ) ;
11) - 27/20 × ( - 5/9 ) - 5/24 × ( - 22/5 ) =
3/4 - ( -11/12 ) = 1 2/3 ;
12) - 36/60 × ( - 5/18 ) - ( - 21/56 ) × ( - 1/3 ) =
1/6 - 1/8 = 1/24 ;
13) 15 × ( 1 + 1/3 - 1/5 ) = 15 × ( 1 1/3 - 1/5 ) =
15 × 1 2/5 = 17 ;
14) 72 × ( 19/24 - 7/12 + 3/8 ) = 72 × ( 5/24 + 3/8 ) = 72 × 7/12 = 42 ;
15) 72/23 × 34/65 + 72/73 × 39/65 =
1 953/1495 + 216/365 = 2 25018/109135 ;
16) 107/89 × 64/70 + 107/89 × 25/70 =
1 309/3115 + 535/1246 = 1 37/40 ;
17) 45/46 × 49/51 - 45/46 × 3/51 =
735/182 - 2 573/850 = - 1 7177/ 9775 ;
18) 34/74 × 122/55 - 34/74 × 48/ 55 =
1 6/55 - 816/2035 = 131/185 ;
19) 3/25 × ( - 5/49 ) + 22/25 × ( - 5/49 ) =
( - 3/245 ) + ( - 2</