Question 835602
First simplify each side. 
{{{3x-6-10=5x-20}}}
{{{3x-16=5x-20}}}
Move knowns to one side, unknowns on the other.
Subtract {{{5x}}} from both sides,
{{{3x-5x-16=5x-5x-20}}}
{{{-2x-16=0-20}}}
{{{-2x-16=-20}}}
Add {{{16}}} to both sides,
{{{-2x-16+16=-20+16}}}
{{{-2x+0=-4}}}
{{{-2x=-4}}}
Divide both sides by {{{-2}}}
{{{(-2x)/-2=-4/-2}}}
{{{(-2/-2)x=-2}}}
{{{(1)x=-2}}}
{{{x=-2}}}