Question 53764
8 is less than X, and X is less than 12:

{{{8 < x < 12}}}

The difference between 8 and 12 is 4. Half of 4 is 2. Therefore, since we want an absolute value inequality, we need to change those values (8 and 12) into numbers with opposite signs. The ones that will work are -2 and 2. Now that we know that, it's pretty easy:

{{{8 < x < 12}}}
{{{8 - 10 < x - 10 < 12 - 10}}}
{{{-2 < x - 10 < 2}}}

{{{abs(x-10) < 2}}}