Factorize completely

$(2x+2y)(x-y)+(2x-2y)(x+y)$

Factorize completely the expression ${{(x+2)}^{2}}-{{(2x+1)}^{2}}$

Simplify the expression $\frac{{{a}^{2}}{{b}^{4}}-{{b}^{2}}{{a}^{4}}}{ab(a+b)}$

Simplify $\frac{3x-y}{xy}-\frac{2x+3y}{2xy}+\frac{1}{2}$ 

Factorize completely $6ax-12by-9ay+8bx$  

Given that  $(2x-1)(x+5)=2{{x}^{2}}-mx-5$, what is the value of m?

Expand the expression $(3a-xy)(3a+xy)$

Simplify $\frac{2{{x}^{2}}-5x-12}{4{{x}^{2}}-9}$

Factorize $5{{y}^{2}}-2ay-3{{a}^{2}}$

Simplify $\frac{\tfrac{1}{x}+\tfrac{1}{y}}{x+y}$