1998 年

If $x=\dfrac{y(z-3)}{3z}$, then $z=$

If $\mathrm{f}(x)=x^2-3x-1$, then $\mathrm{f}(a)+\mathrm{f}(-a)=$

Solve $x^2+5x-6\le 0$.

Solve the simultaneous equations: $\begin{cases}2x+\dfrac{3}{y}=-1\\ x-\dfrac{1}{y}=7\end{cases}$.

If $(x+3)^2-(x+1)(x-3)\equiv P(x+1)+Q$, find $P$ and $Q$.

Let $\mathrm{f}(x)=2x^3-x^2-7x+6$. It is known that $\mathrm{f}(-2)=0$ and $\mathrm{f}(1)=0$. $\mathrm{f}(x)$ can be factorized as

$\dfrac{(2^m)^2}{8^m}=$

Factorize $x^2-y^2+2x+1$.

If the equation $x^2-6x+k=0$ has real roots, find all possible values of $k$.

Solve $(x-1)(x-3)=x-3$.