Hey there!!
Problem given :
3 I x - 1 I ≥ 12
Divide 3 on both sides
I x - 1 I ≥ 4
Now, in order to remove the modulus , you add a ± symbol on the other side and you need to switch the symbol for the negative values
Now,
( x - 1 ) ≥ ±4
Let's take negative first
x - 1 ≤ -4
x ≤ -3 ( this is one of the answer )
Now, lets take the positive sign
x - 1 ≥ 4
x ≥ 5
Hence, the two values are x ≤ - 3 and x ≥ 5
Hope my answer helps!
