Given that f, of, x, equals, x, squared, minus, 6, x, minus, 40f(x)=x 2 −6x−40 and g, of, x, equals, x, minus, 10g(x)=x−10, find left bracket, f, dot, g, right bracket, left bracket, x, right bracket(f⋅g)(x) and express the result as a polynomial in simplest form.