Tính a) |1+|1+|1+x|||=4 b)$\frac{6}{25}$ -||3x-$\frac{1}{5}$|-1|=-2

Đáp án:

Giải thích các bước giải: \(\begin{array}{l}a)\,\,\left| {1 + \left| {1 + \left| {1 + x} \right|} \right|} \right| = 4\\ \Rightarrow 1 + \left| {1 + \left| {1 + x} \right|} \right| = 4\,\,\\ \Rightarrow \,\,\,\,\,\,\,\left| {1 + \left| {1 + x} \right|} \right| = 3\\ \Rightarrow 1 + \left| {1 + x} \right| = 3\\ \Rightarrow \left| {1 + x} \right| = 2\\ \Rightarrow 1 + x = 2\,\,\,\,hoac\,\,\,\,1 + x = - 2\\ \Rightarrow \,\,\,\,\,\,\,\,x = 1\,\,\,\,\,hoac\,\,\,\,\,\,\,\,\,\,x = - 3\\b)\,\frac{6}{{25}} - \left| {\left| {3x - \frac{1}{5}} \right| - 1} \right| = - 2\\\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\left| {\left| {3x - \frac{1}{5}} \right| - 1} \right| = \frac{6}{{25}} + 2\\\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\left| {\left| {3x - \frac{1}{5}} \right| - 1} \right| = \frac{{56}}{{25}}\\\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\left| {3x - \frac{1}{5}} \right| - 1 = \frac{{56}}{{25}}\,\,\,hoac\,\,\,\,\,\left| {3x - \frac{1}{5}} \right| - 1 = \frac{{ - 56}}{{25}}\\\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\end{array}\) Câu b) em giải tiếp 2 trường hợp nhé!