\(\left(2x-3\right)\left(2x+3\right)=4x^2-9\)
\(\left(3x-4\right)\left(3x+4\right)=9x^2-16\)
\(\left(2x-5\right)\left(2x+5\right)=4x^2-25\)
\(\left(4x-1\right)\left(4x+1\right)=16x^2-1\)
\(\left(x-\dfrac{1}{2}\right)\left(x+\dfrac{1}{2}\right)=x^2-\dfrac{1}{4}\)
\(\left(x-\dfrac{1}{3}\right)\left(x+\dfrac{1}{3}\right)=x^2-\dfrac{1}{9}\)