1) 4 4/9 * 5/8 + 5/8 * 3 5/9= 5/8 * (4 4/9 + 3 5/9 ) =
= 5/8 * 8 = 5/8 * 8/1 = 5/1 = 5
2)3 7/8 * 4/5 - 1 5/8 * 4/5 = 4/5 * (3 7/8 - 1 5/8) =
=4/5 * 2 2/8 = 4/5 * 2 1/4 = 4/5 * 9/4 = 9/5 =
=1 4/5 = 1,8
3) 2 11/15 * 1 1/19 - 1 1/19 * 3/10 - 1 1/6 * 1 1/19=
= 1 1/19 * ( 2 11/15 - 3/10 - 1 1/6) =
= 20/19 * ( 2 22/30 - 9/30 - 1 5/30 )=
= 20/19 * 1 8/30 = 20/19 * 38/30 = (2*2)/(1*3)=
= 4/3 = 1 1/3
4) 4 7/9 * 1 13/14 - 3 7/12 * 1 13/14 + 1 13/14 * 1 13/18 =
= 1 13/14 * ( 4 7/9 - 3 7/12 + 1 13/18 ) =
= 27/14 * ( 4 28/36 - 3 21/36 + 1 26/36) =
= 27/14 * 2 33/36 = 27/14 * 2 11/12 =
= 27/14 * 35/12 = (9*5)/(2*4)= 45/8 =
= 5 5/8 = 5,625