If $\frac{x}{y}+\frac{y}{x}=-1(x, y \neq 0),$ the value of $x^{3}-y^{3}$ is
$1$
$\frac{1}{2}$
$-1$
$0$
Expand the following:
$\left(4-\frac{1}{3 x}\right)^{3}$
If both $x-2$ and $x-\frac{1}{2}$ are factors of $p x^{2}+5 x+r,$ show that $p=r$
Expand the following:
$(3 a-5 b-c)^{2}$
The following expressions are polynomials? Justify your answer:
$\frac{1}{7} a^{3}-\frac{2}{\sqrt{3}} a^{2}+4 a-7$
If $p(x)=x^{2}-4 x+3,$ evaluate $: p(2)-p(-1)+p\left(\frac{1}{2}\right)$