Question 12294
50=15-6(2x-5)
{{{50=15-6*2x-6*(-5)}}}
{{{50=15-12x+30}}}
{{{50=15+30-12x}}}
{{{50=45-12x}}}
{{{12x = 45 - 50}}}
{{{12x = -5}}}
{{{x = -5/12}}}

and,
3(-6x+9)-10x=1
{{{3*(-6x)+3*9-10x=1}}}
{{{-18x+27-10x=1}}}
{{{-18x-10x=1-27}}}
{{{-28x=-26}}}
{{{x=-26/-28}}}
{{{x=26/28}}}
{{{x=13/14}}}

OK