This is about absolute value inequalities.
The set of possible values of x that make the statement true are; x = {-2, -1, 0, 1}
We are told that when it is multiplied by 3 and 1 added to it, it is between - 8 and 7. This means it is greater than -8 but less than 7.
Thus;
3x + 1 > -8 - - - (eq 1)
3x + 1 < 7 - - - (eq 2)
3x + 1 > -8
Subtract 1 from both sides to get;
3x > -9
x > -9/3
x > -3
3x + 1 < 7
Subtract 1 from both sides to get;
3x < 7 - 1
3x < 6
x < 6/3
x < 2
Thus, we can write that;
-3 < x < 2
Thus, the set of possible values of x are; x = {-2, -1, 0, 1}
Read more at; brainly.com/question/18119747