2009 年

$2^n\cdot 3^n=$

If $P=\dfrac{VT}{R}-2$, then $T=$

$\dfrac{1}{a-2}-\dfrac{2}{1-a}=$

$(3x-5)(2x^2+5x-3)=$

If $a$ and $b$ are constants such that $a(x^2-x)+b(x^2+x)\equiv 2x^2+4x$, then $a=$

Let $\mathrm{f}(x)=x^2-9x+c$, where $c$ is a constant. If $\mathrm{f}(-1)=8$, then $c=$

In the figure, the area of the trapezium is $96\text{ cm}^2$. Find $x$.

If the quadratic equation $x^2+bx+4b=0$ has equal roots, then $b=$

If $x$ is a positive integer satisfying the inequality $x-5\le 1-x$, then the least value of $x$ is

If a dictionary is sold at its marked price, then the percentage profit is $30\%$. If the dictionary is sold at a $20\%$ discount on its marked price, then the profit is $\$5$. Find the cost of the dictionary.