an expression in the form (a-b)² is expanded to the form a²-2ab+b²
you can also expand it to (x-6)×(x-6) then multiply the first term by the first the outer term by the outer term the inner term by the inner term and the last term by the last term (foil)
the first terms are x and x = x² the outer terms are x and -6 = -6x the inner terms are also x and -6 = -6x
