Answer:
2. An absolute.value cannot be negative
Step-by-step explanation:
I.I'll explain it short why absolute.value cannot be negative
 Given |4x - 7| = -1
      4x  = -1 + 7
       4x = 6
        x = 3/2
II. Prove by x = 3/2
      |4([tex]\frac{3}{2}[/tex]) - 7| = -1
      |2(3) - 7| = -1
      |6 - 7| = -1
      | -1 | = -1
       1  = -1  false, not true
III. Absolute value is came from [tex]\sqrt{|x|}^{2}[/tex]
As you knew square root value cannot be negative
So absolute.value cannot be negative.
Ask me for anything.