Giải thích các bước giải:
\(\begin{array}{l}
a.DK:\frac{2}{3}x - \frac{1}{5} \ge 0\\
\to \frac{2}{3}x \ge \frac{1}{5}\\
\to x \ge \frac{3}{{10}}\\
b.Do:{x^2} \ge 0\forall x \in R\\
\to {x^2} + 2 > 0\forall x\\
\to DK:x \in R\\
c.DK:\left\{ \begin{array}{l}
1 + x \ge 0\\
2x - 3 > 0
\end{array} \right. \to \left\{ \begin{array}{l}
x \ge - 1\\
x > \frac{3}{2}
\end{array} \right.\\
\to x > \frac{3}{2}\\
d.DK:\left\{ \begin{array}{l}
3x - 5 \ge 0\\
x - 4 > 0
\end{array} \right. \to \left\{ \begin{array}{l}
x \ge \frac{5}{3}\\
x > 4
\end{array} \right.\\
\to x > 4
\end{array}\)
