Question 1097235

A number:  x
Twice a number: 2x
No less than 10 units from -1:     | 2x - (-1) | >= 10
                                             
| 2x + 1 | >= 10

Two cases to consider, the first is  2x + 1 <= -10

2x + 1 <= -10 
  2x <= -11
   x <= -11/2

—
 2nd case:  2x + 1 >= 10
 2x + 1 >= 10
  2x >= 9
   x >= 9/2

—

The solution regions are  {{{ highlight(x <= -11/2) }}} and {{{ highlight(x >= 9/2) }}}