Question 826071
First off this is about usage of signs not raticals.
{{{8x-2=-9+7x}}} start by subtracting 7x from both sides
{{{8x-7x-2=-9+7x-7x}}} add like terms
{{{x-2=-9}}} add 2 to both sides 
{{{x-2+2=-9+2}}} add like terms
{{{highlight(x=-7)}}}