# How do you simplify (d^2)-4?

We know that color(blue)(a^2 - b^2 = (a+b)(a-b)
And ${d}^{2} - 4 = {d}^{2} - {2}^{2}$
Using the identity, we can write ${d}^{2} - {2}^{2}$ as color(green)((d+2)(d-2)