18. Fill in the blank with an appropriate inequality a. If \( x<-2 \), then \( 1-\mathrm{x} \) b. If \( \frac{1}{2}\left(3 x-\frac{2}{3}\right) \leq x+5 \), then \( x+\frac{7}{3} \) c. If \( 3 x-1>5 x-3 \), then \( 3 x \)

If \( x < -2 \), then \( 1 - x > 3 \). This is because when we subtract a negative number, it adds to the value, and since \( x \) is less than -2, \( 1 - x \) must be greater than 3. If \( \frac{1}{2}\left(3 x - \frac{2}{3}\right) \leq x + 5 \), then \( x + \frac{7}{3} \geq \frac{1}{2} \). After solving the inequality, we find that the values of \( x \) must satisfy this condition, ensuring \( x \) is bounded above in a specific manner. If \( 3x - 1 > 5x - 3 \), then \( 3x < 2 \). Once we rearrange with simple algebraic manipulation, we simplify the inequality to reflect that \( 3x \) must be less than 2 as long as the given condition holds.