1982 年

$\dfrac{2a}{a^2-4b^2}+\dfrac{1}{2b-a}=$

If $x=\dfrac{1}{\dfrac{1}{y}+\dfrac{2}{z}}$, then $y=$

If $10^{kx+a}=P$, then $x=$

$\alpha$ and $\beta$ are the roots of the equation $x^2-5x-7=0$. What is the equation whose roots are $\alpha+1$ and $\beta+1$?

What are the roots of the equation $(x-3)^2(x+1)=-(x+1)^2(x-3)$?

$5-9x-2x^2>0$ is equivalent to

What will $\$P$ amount to in 3 years' time, if interest is compounded monthly at 12% per annum?

A child spent $\dfrac{1}{10}$ of his saving on a shirt and $\dfrac{1}{5}$ of his savings on a pair of trousers. He then spent 30% of the rest of his savings on books. What percentage of his saving did he spend altogether?

The rent of a flat is raised by 30% every two years beginning from a fixed date. Counting from that date, after how many years will the rent just exceed twice the original rent?

A man drives 20 km at 40 km/h. At what speed must he drive on his return journey so that the average speed for the double journey is 60 km/h?