9t+4t-286=0
13t=286
t=286:13
t=22
14x+9x+88=272
23x=272-88
23x=184
x=184:23
x=8
25x-16x+54=162
9x=162-54
9x=108
x=108:9
x=12
144:(x-3)=36
x-3=144:36
x-3=4
x=4+3
x=7
21(y-8)=84
21y-168=84
21y=84+168
21y=252:21
у=12
(x+67):18=4
x+67=4*18
x+67=72
x=72-67
x=5
9t+4t-286=0
13t=286
t=286:13
t=22
14x+9x+88=272
23x=272-88
23x=184
x=184:23
x=8
25x-16x+54=162
9x=162-54
9x=108
x=108:9
x=12
144:(x-3)=36
x-3=144:36
x-3=4
x=4+3
x=7
21(y-8)=84
21y-168=84
21y=84+168
21y=252:21
у=12
(x+67):18=4
x+67=4*18
x+67=72
x=72-67
x=5