2006 年

$(2x)^3\cdot x^3=$

If $2x-5y=7$, then $y=$

$\dfrac{1}{x+1}-\dfrac{1}{x-1}=$

$pr+qr-ps-qs=$

If $\mathrm{f}(x)=\dfrac{x}{1+x}$, then $\mathrm{f}(3)\,\mathrm{f}\left(\dfrac{1}{3}\right)=$

Which of the following is an identity / are identities? I. $x^2-4=0$ II. $x^2-4=(x-2)^2$ III. $x^2-4=(x+2)(x-2)$

The figure shows the graph of $y=\mathrm{f}(x)$. If $\mathrm{f}(x)$ is a quadratic function, then $\mathrm{f}(x)=$

Solve $3x^2=21x$.

Find the range of values of $k$ such that the quadratic equation $x^2+2x-k=2$ has two distinct real roots.

The marked price of a car is $50\%$ higher than the cost. If the car is sold at a $20\%$ discount on the marked price, then the percentage profit is