2х+9=13-х
2х+х=13-9
3х=4
х=4:3
х=1 1/3
14-y=19-11y
-y+11y=19-14
10y=5
y=0.5
0.5а+11=4-3а
0.5а+3а=4-11
3.5а=-7
а=-7:3.5
а=-2
1.2n+1=1-n
1.2n+n=1-1
2.2n=0
n=0:2.2
n=0
1.7-0.3м=2+1.7м
-0.3м-1.7м=2-1.7
-2м=0.3
м=0.3:(-2)
м=-0.15
0.8х+14=2-1.6х
0.8х+1.6х=2-14
2.4х=-12
х=-12:2.4
х=-5