Question

giải bất phương trình |2x+3| ≥18

Answer 1

= máy tính

Answer 2

đen thui z

Answer 3

8

Answer 4

\(\left|2x+3\right|\ge18\)

\(\Leftrightarrow2x+3>18;2x+3< -18\)

*) \(2x+3>18\)

\(\Leftrightarrow2x>15\)

\(\Leftrightarrow x>\dfrac{15}{2}\)

*) \(2x+3< -18\)

\(\Leftrightarrow2x< -21\)

\(\Leftrightarrow x< -\dfrac{21}{2}\)

Vậy \(x>\dfrac{15}{2}\); \(x< -\dfrac{21}{2}\)

Answer 5

đen quá 

Answer 6

\(\left|2x+3\right|\ge18\)

\(\Leftrightarrow\left[{}\begin{matrix}2x+3\ge18\\2x+3\le-18\end{matrix}\right.\)

\(\Leftrightarrow\left[{}\begin{matrix}x\ge\dfrac{15}{2}\\x\le-\dfrac{21}{2}\end{matrix}\right.\)