When it comes to squaring a binomial usually we use the foil method because we can translate exponential form to standard form. (Exponential: 4^2 = 2 x 2 :standard) but there is a simplest way in squaring binomial expression. Let us consider this given expression (2x - 4). Take note that the sign of the middle term varies depending upon the sign that seperates the first term and the second term in the given binomial. Since (-) seperates 2x from 4x therefore the sign of the middle term will be negative. Just simply follow this pattern Square the first term, twice the product of the first and second term, square the second/last term. It goes like this. First is square the first term (2x)^2 = 2^2 x^2 = 4x^2. *take note that we need to distribute the exponent inside the given expression* Next since we need twice the product of the first and second term it becomes 2(2x)(-4) = -16x. Last is to square the last term (-4)^2 = (-4)(-4) = 16. Our final answer will be 4x^2 - 16x + 16. Through a lot of practice we can mentally square Binomials! I hope this thing can help you guys!