Đáp án:
c,` | x + 4/15| - | -3,75| = -| -2 , 15|`
`| x + 4/15| - 3,75 = -2,15`
`| x + 4/15| = -2,15 + 3,75 = 1,6 = 8/5`
⇒\(\left[ \begin{array}{l}x + \frac{4}{15} = \frac{8}{5}\\x+ \frac{4}{15}= -\frac{8}{5}\end{array} \right.\)
⇒\(\left[ \begin{array}{l}x = \frac{4}{3}\\x = -\frac{28}{15}\end{array} \right.\)
Vậy `x \in { 4/3 ; -28/15}`