Question

trị tuyệt đối của x - 7 phần 10 - 1 phần 5 = 0

Answer 1

\(\left|\dfrac{x-7}{10}\right|-\dfrac{1}{5}=0\)

\(\Rightarrow\left|\dfrac{x-7}{10}\right|=\dfrac{1}{5}\)

\(\Rightarrow\dfrac{x-7}{10}=\dfrac{1}{5}\text{ hoặc }\dfrac{x-7}{10}=-\dfrac{1}{5}\)

\(\Rightarrow x-7=2\text{ hoặc }x-7=-2\)

\(\Rightarrow x=9\text{ hoặc }x=5\)

Vậy x = 9 hoặc x = 5

Answer 2

\(\left|\dfrac{x-7}{10}\right|-\dfrac{1}{5}=0\)

\(\left|\dfrac{x-7}{10}\right|=\dfrac{1}{5}\)

⇔ \(\left[{}\begin{matrix}\dfrac{x-7}{10}=\dfrac{1}{5}\\\dfrac{x-7}{10}=-\dfrac{1}{5}\end{matrix}\right.\)

⇔ \(\left[{}\begin{matrix}x=9\\x=5\end{matrix}\right.\)