A brokerage firm charges 5% commission on gold purchases in amounts from $30 to $4000. For purchases exceeding $4000 the firm charges 2% of the amount purchased plus a $13 handling fee. Let x denote the amount of gold purchased (in dollars), and let for) be the commission charge as a function of x. Complete parts (a) and (0) below. (b) Find 4000) and K4500)- f{4000) = 1 (Type an integer or a decimal.) H4500) = j (T ype an integer or a decimal.)