1981 年

$\dfrac{(a^2b^{-3})^2}{a^{-2}b}=$

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

If $x=\dfrac{-bx+ay-c}{a+by}$, then $y=$

If $H=K+\dfrac{M}{4\pi(r^2+l^2)^n}$ and $r>0$, then $r=$

If $f(x)=x^2+x+1$, then $f(x+1)-f(x)=$

If $\log_{10}x+\log_{10}4=\log_{10}(x+4)$, what is the value of $x$?

It is given that $x(2x+3)=x(3x-4)$. $x=$ ?

$2y-3>4y+2x+5$ is equivalent to

The $n$th term of the arithmetic progression $2, 6, 10, 14, \ldots$ is

If $3x-2y=x+3y$, then $x^2:y^2=$