The common ratio looks like -2 (-11 * -2 =22) and the missing terms are -44 and 352. (22*-2=-44, -176*-2=352).
        
             
        
        
        
There are 6 different ways:
23,598
23,958
25,398
25,938
29,538
29,358
        
             
        
        
        
∈  ≤ ≥
-6 ≤ 2x + 6 ≤ 6 ( seperate the two inequalities)
2x + 6 ≥ - 6
2x + 6 ≤ 6 (solve the inequalities)
x ≥ -6
x ≤ 0 (find the intersection)
solution is : x ∈  { -6, 0 }