Question 960376
Your setup is wrong.
{{{7N}}} 
"is" is the equivalent of "=".
"9 less than the product" is the product minus 9.
{{{7N=N(-20)-9}}}
{{{7N=-20N-9}}}
{{{27N=-9}}}
{{{N=-9/27}}}
{{{N=-1/3}}}