1) - 2 4/27 + 1 5/18 = - 2 8/54 + 1 15/24 = - 1 62/54 + 1 15/24 = - 47/54
2) 12 1/4 + 2 1/2 = 12 1/4 + 2 2/4 = 14 3/4 = 59/4
3) 5,4d * ( - 47/54 ) = 59/4
5,4d = 59/4 : ( - 47/54 )
5,4d = - 59 27 / 2 47
5,4d = - 1593/94
d = - 1593/94 : 27/5
d = - 295/94
d = - 3 13/94