Factorisation of Polynomials using Algebraic Identities

Simplify:

$x^2\times \left(\frac{x}{y}-\frac{y}{x}\right)\times \left(\frac{y}{x}+\frac{x}{y}\right)\times y^2$

Find the factors of $(a^2-b^2-c^2+d^2{)}^2-4(ad-bc{)}^2$

Find the value of ${10}^3-{\left(5\right)}^3-{\left(5\right)}^3$.

Find the value of $\text{'}x\text{'}$ when: $43x={\left(28\right)}^2-{\left(15\right)}^2$

The value of ${\left(84\right)}^2-{\left(83\right)}^2$ is

If $a^2-4a-1 = 0$, find the value of  $a^2 -\frac{1}{a^2}$

The factors of $81p^2-144q^2$ are