Đáp án:
Giải thích các bước giải:
$M=\left |1\dfrac{1}{5}-x \right |+\left |x-\dfrac{1}{5} \right | -3\dfrac{1}{5}$
$M=\left |\dfrac{6}{5}-x \right | +\left |x-\dfrac{1}{5} \right | -\dfrac{16}{5}$
$a,\text{Với $x\geq1\dfrac{1}{5}<=>x\geq\dfrac{6}{5}$ thì ta có:}$
$M=\dfrac{6}{5}-x+x-\dfrac{1}{5}-\dfrac{16}{5}$
$M=\left (\dfrac{6}{5}-\dfrac{1}{5}-\dfrac{16}{5} \right ) -(x-x)$
$M=1-\dfrac{16}{5}$
$M=-\dfrac{11}{5}$
$\text{Vậy $M=-\dfrac{11}{5}$ khi $x\geq1\dfrac{1}{5}$}$
$b,\text{Với $x\leq\dfrac{1}{5}$ thì ta có}$
$M=x-\dfrac{6}{5}+\dfrac{1}{5}-x-\dfrac{16}{5}$
$M=(x-x)-\left (\dfrac{6}{5}-\dfrac{1}{5}+\dfrac{16}{5} \right )$
$M=-\dfrac{21}{5}$
$\text{Vậy $M=-\dfrac{21}{5}$ với $x\leq\dfrac{1}{5}$}$
$c,\text{Với $\dfrac{1}{5}<x<1\dfrac{1}{5}$ thì ta có:}$
$M=x-\dfrac{6}{5}+x-\dfrac{1}{5}-\dfrac{16}{5}$
$M=(x+x)-\left (\dfrac{6}{5}+\dfrac{1}{5}+\dfrac{16}{5} \right )$
$M=2x-\dfrac{23}{5}$
$\text{Vậy $M=2x-\dfrac{23}{5}$ với $\dfrac{1}{5}<x<1\dfrac{1}{5}$}$
Chúc bạn học tốt.
