1989 年

$3^{n-1}\times 3^{n+1}=$

$\dfrac{27x^3-8}{3x-2}=$

$\sqrt{\dfrac{x}{\sqrt{x}}}=$

If $\mathrm{f}(x)=\dfrac{x}{1-x}$, then $\mathrm{f}\left(\dfrac{1}{x}\right)=$

Which of the following systems of inequalities is represented by the shaded region in the figure?

Let $\mathrm{f}(x)=ax^2-5$ and $\mathrm{g}(x)=27x^3-18x+4$. If both expressions leave the same remainder when divided by $3x+1$, then $a=$

If $3x>-2y$ and $y<0$, then

Given that $r$ is the only real root of $x^5+x-1=0$, which of the following ranges contains $r$?

If $z$ varies inversely as $x$ and directly as $y$, then

Which of the following is/are true?

I. If both 2 and 3 are factors of $m$, then 6 is also a factor of $m$. II. If 15 is a factor of $n$, then both 3 and 5 are factors of $n$. III. If $p$ is a multiple of both 4 and 6, then $p$ is also a multiple of 24.