Question

Tìm x:

a, -4/9 - 5/9 : x = 1/18

b, |x| = 1/2

c, x. ( x - 1/3 ) = 0

d, ( x - 2 ).( x + 3 ) < 0

e, ( x - 2 ).( x + 3 ) > 0

Answer 1

\(a)\dfrac{-4}{9}-\dfrac{5}{9}:x=\dfrac{1}{18}\)

\(\Leftrightarrow\dfrac{5}{9}:x=\dfrac{-8}{18}+\dfrac{-1}{18}\)

\(\Leftrightarrow\dfrac{5}{9}:x=\dfrac{-1}{2}\)

\(\Leftrightarrow x=\dfrac{5}{9}.\left(-2\right)\)

\(\Leftrightarrow x=\dfrac{-10}{9}\)

\(b)\left|x\right|=\dfrac{1}{2}\)

\(\Leftrightarrow x\in\left\{-\dfrac{1}{2};\dfrac{1}{2}\right\}\)

\(c)x\left(x-\dfrac{1}{3}\right)=0\)

\(\Leftrightarrow\left[{}\begin{matrix}x=0\\x-\dfrac{1}{3}=0\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x=0\\x=\dfrac{1}{3}\end{matrix}\right.\)

\(\Leftrightarrow x\in\left\{0;\dfrac{1}{3}\right\}\)

Answer 2

a) x=\(\dfrac{-10}{9}\)

b)x∈{\(\dfrac{1}{2}\); \(\dfrac{-1}{2}\)}