1) (2 : 3/5) + (3/5:2) + (1 1/2 :6) + (6: 1 1/2) = 10/3 + 3/10 + 1/4 + 4 =
=(100+9)/30 + 4 1/4 = 109/30 + 17/4 = (218+255)/60 = 473/60 = 7 53/60 - ОТВЕТ
2) (6 1/4 * 8) - (3 2/3* 5 1/2) + (2 2/5 *4 7/12) = 50 - 20 1/6 + 11 = 40 5/6 - ОТВЕТ
3) (2 1/2*48) - (3 2/3 : 1/18) + (5 5/12 : 7/36) =
= (5*48/2) - (11*18/3) + (65/12*36/7) =
= 120 - 66 + 27 6/7 = 81 6/7 - ОТВЕТ
4) ( 13 1/2 : 1 1 /3) + (16 1/2 * 1 5/11) + (19 1/4 : 4/25) = 10 1/8 + 24 +120 5/16
= 154 7/16 - ОТВЕТ
=