a]
[tex]-3x+5=20 \ \ |-5\\\\-3x=15 \ \ |:(-3)\\\\\huge\boxed{x=-5}[/tex]
b]
[tex]-2x+6=4 \ \ |-6\\\\-2x=-2 \ \ |:(-2)\\\\\huge\boxed{x=1}[/tex]
c]
[tex]12x-16=20 \ \ |+16\\\\12x=36 \ \ |:12\\\\\huge\boxed{x=3}[/tex]
d]
[tex]11-x=19 \ \ |-11\\\\-x=8 \ \ |:(-1)\\\\\huge\boxed{x=-8}[/tex]
e]
[tex]4+3x=31 \ \ |-4\\\\3x=27 \ \ |:3\\\\\huge\boxed{x=9}[/tex]
f]
[tex]\frac{1}{2}x-6=2 \ \ |+6\\\\\frac{1}{2}x=8 \ \ |\cdot2\\\\\huge\boxed{x=16}[/tex]
