358.
1) A= ab/6
2) B= 27/4 · 56/45·xy = 27·14/45·xy = 378/45 ·xy = 8,4xy
3) C = 13·4/3 ·dc = 52/3·cd = 17'1/3 ·cd
4) 55/3·13/11·9/13·abc = 15abc
361.
1) (1/2+1/3 - 1/4)·12/7 = (12+4 -3)/12 · 12/7 = 13/7 = 1'6/7
2) (4/7+5/21 - 2/3)·7/3 = (12+5 - 14)/21 ·7/3 = 3·/9 =1/9
3) (17/12 + 43/18 - 11/9)·48/31 = (51+86 - 44)/36 · 48/31 =
= 93/3 · 4/31 = 4