Question

Tìm x, biết:

a) |x|= 3,5

b) |1 - x| + 0,73 = 3

c) \(\dfrac{-5}{8}\) + x = \(\dfrac{4}{9}\)

Answer 1

a) \(\left|x\right|=3,5\)

\(\Rightarrow\left[{}\begin{matrix}x=3,5\\x=-3,5\end{matrix}\right.\)

b) \(\left|1-x\right|+0,73=3\)

\(\Rightarrow\left|1-x\right|=3-0,73\)

\(\Rightarrow\left|1-x\right|=2,27\)

\(\Rightarrow\left[{}\begin{matrix}1-x=2,27\\1-x=-2,27\end{matrix}\right.\)

\(\Rightarrow\left[{}\begin{matrix}x=-1,27\\x=3,27\end{matrix}\right.\)

c) \(\dfrac{-5}{8}+x=\dfrac{4}{9}\)

\(\Rightarrow x=\dfrac{4}{9}-\left(\dfrac{-5}{8}\right)\)

\(\Rightarrow x=\dfrac{77}{72}\)