Answer:
a
Step-by-step explanation:
The absolute value function always gives a positive result, however, the expression inside can be positive or negative, thus
x + 7 = 9 or - (x + 7) = 9
Solve both equations
x + 7 = 9 ( subtract 7 from both sides )
x = 2
OR
-(x + 7) = 9, that is
- x - 7 = 9 ( add 7 to both sides )
- x = 16 ( multiply both sides by - 1 )
x = - 16
Solutions are x = 2, x = - 16 → a
