4 - 5/9 * (-1.8) = 4 - 5/9 * (- 9/5) = 4+1=5
у: (- 1 7/9 ) = 3/8 : 4/5
4/5 * у = 3/8 * (- 16/9)
4/5 у = - 2/3
у= -2 /3 : 4/5 = - 2/3 * 5/4
у= - 5/6
-----------------------
- 5/6 : ( - 1 7/9 ) = 3/8 : 4/5
- 5/6 * (- 9/16) = 3/8 *5/4
15/ 32 = 15/32
3(х-2,4) - (2х+5,8)=
= 3х-7,2 -2х -5,8=
=х- 13