Đáp án:
e, `| x - 0,25| - 5 2/3 = 0`
`| x - 0,25| - 17/3 = 0`
`|x - 0,25| = 0 + 17/3=17/3`
⇒\(\left[ \begin{array}{l}x - 0,25 =\frac{17}{3} \\x - 0,25 =-\frac{17}{3} \end{array} \right.\)
⇒\(\left[ \begin{array}{l}x = \frac{71}{12} \\x =-\frac{65}{12} \end{array} \right.\)
Vậy `x ∈ { 71/12 ; -65/12}`
f, `19/6 - | x - 8/7| = 9/4`
`| x - 8/7| =19/6 - 9/4 = 11/12`
⇒\(\left[ \begin{array}{l}x - \frac{8}{7}=\frac{11}{12} \\x -\frac{8}{7}=- \frac{11}{12} \end{array} \right.\)
⇒\(\left[ \begin{array}{l}x =\frac{173}{84} \\x =\frac{19}{84} \end{array} \right.\)
Vậy `x ∈ {173/84 ; 19/84}`
g, `| x - 7/5| = | 3x + 11/3|`
⇒\(\left[ \begin{array}{l}x -\frac{7}{5}= 3x + \frac{11}{3} \\x - \frac{7}{5} = -3x -\frac{11}{3} \end{array} \right.\)
⇒\(\left[ \begin{array}{l}x =-\frac{38}{15} \\x = -\frac{17}{30} \end{array} \right.\)
Vậy `x ∈ {-38/15 ; -17/30}`
g, `| -7/3x + 5/6| = | x + 11/4|`
⇒\(\left[ \begin{array}{l}\frac{-7x}{3} + \frac{5}{6} = x + \frac{11}{4} \\\frac{-7x}{3} + \frac{5}{6} = -x - \frac{11}{4}\end{array} \right.\)
⇒\(\left[ \begin{array}{l}x = -\frac{23}{40}\\x=\frac{43}{16}\end{array} \right.\)
Vậy `x ∈ {-23/40 ; 43/16}`
