Đáp án:
Giải thích các bước giải:
$2.$
$a,x+\dfrac{17}{10}=\dfrac{3}{5}$
$⇔x=\dfrac{3}{5}-\dfrac{17}{10}$
$⇔x=-\dfrac{11}{10}$
$b,x-\dfrac{1}{3}=x+\dfrac{1}{6}$
$⇔x-x=\dfrac{1}{6}+\dfrac{1}{3}$
$⇔0x=\dfrac{1}{2}$
$\text{⇒Phương trình vô nghiệm.}$
$c,|x+25|=42$
⇔\(\left[ \begin{array}{l}x+25=42\\x+25=-42\end{array} \right.\)
⇔\(\left[ \begin{array}{l}x=17\\x=-67\end{array} \right.\)
$d,|x-12|+15=17$
$⇔|x-12|=2$
⇔\(\left[ \begin{array}{l}x-12=2\\x-12=-2\end{array} \right.\)
⇔\(\left[ \begin{array}{l}x=15\\x=10\end{array} \right.\)
$e,(x+7)^2=81$
⇔\(\left[ \begin{array}{l}x+7=9\\x+7=-9\end{array} \right.\)
⇔\(\left[ \begin{array}{l}x=2\\x=-16\end{array} \right.\)
$g,(x-12)^3=27$
$⇒x-12=3$
$⇒x=15$
Chúc em học tốt.
