1) 0.8
на второй вопрос ответ примерно -5(67:70)
5/13 и 7/8
40/104 и 91/104
40/104<91/104
5/13<7/8
7/13 и 5/7
49/91 и 65/91
49/91<65/91
7/13<5/7
3/7 и 5/8
24/56 и 35/56
24/56<35/56
3/7<5/8
4/9 и 1/12
16/36 и 3/36
16/36>3/36
4/9>1/12
39+(75-56)=39+19=58
93-(42+25)=93-67=26
<span>2дм8см+46см=20см+8см+46см=74см
(7дм3см-26см)+5дм7см=(70см+3см-26см)+50см+7см=47см+57см=104см
86см-(33см-26см)+7дм3см=86см-7см+70см+3см=152см</span>
60 : 12/13 = 60/1 х 13/12= 65. 19/20 : 3,8 = 19/20 : 38/10 = 19/20 х 10/38 = 1/4. 15/32 : ( 3 4/7 х 2 5/8) = 15/32 : ( 25/7 х 21/8) = 15/32 : 75/8= 15/32 х 8/75 = 1/20.
( 7/9 + 0,7 - 5/6) : 3 13/15 = ( 7/9 + 7/10 - 5/6) : 58/15 = ( 70/90 + 63/90 - 5/6) : 58/15= ( 133/90 - 75/90) : 58/15 = 58/90 : 58/15 = 58/90 х 15/58 = 6.