1) (2х+4)*20 -85=35
(2х+4)*20= 120
2х+4 = 6
2х=2
х=1
2) 32+(136-8х):4=64
(136-8х):4=32
136-8х=128
8х=8
х=1
3) (21+75:(2х+13))*5=120
21+75:(2х+13)=24
75:(2х+13) = 3
2х+13 = 25
2х=12
х=6
4) 12*(32-(36+8х):5)=144
32-(36+8х):5 =12
(36+8х):5 =20
36+8х=100
8х=64
х=8