Question 789557
{{{n}}}= the number
{{{n-10}}}= the difference between a number and 10 ( according to a common interpretation)
{{{n+1}}}= the sum of the number and 1
 
The way I read the problem, what it says in words translates as
{{{2(n-10)=3(n+1)}}}
 
Solving:
{{{2(n-10)=3(n+1)}}}
{{{2n-2*10=3n+3*1}}}
{{{2n-20=3n+3}}}
{{{2n-20-3=3n}}}
{{{2n-23=3n}}}
{{{-23=3n-2n}}}
{{{-23=n}}}