1997 年

Express $\pi^2$ as a decimal correct to 3 significant figures.

If $2^x\cdot 8^x=64$, then $x=$

If $\dfrac{a+x}{b+x}=\dfrac{c}{d}$ $(c\ne d)$, then $x=$

$9-a^2-b^2+2ab=$

If $\log(x+a)=2$, then $x=$

If $2x^2+x+m$ is divisible by $x-2$, then it is also divisible by

Which of the following is/are an identity/identities? I. $x^2=4$ II. $(2x+3)^2=4x^2+12x+9$ III. $(x+1)^2=x^2+1$

Solve $\begin{cases}\dfrac{3}{x}-y=1\\[1ex] 2y-\dfrac{1}{2x}=1\end{cases}$.

Which of the following systems of inequalities has its solution represented by the shaded region in the figure?

There are $1\,200$ students in a school, of which $640$ are boys and $560$ are girls. If $55\%$ of the boys and $40\%$ of the girls wear glasses, what percentage of students in the school wear glasses?