Answer all the parts that follow.
(i) State the rule about two real numbers whose product is zero.
(ii) Explain briefly how writing a quadratic equation in the form of a product of two binomials together with the rule in (i) helps in finding its solutions.
(iii) Use your explanation from (ii) to solve (x+7)(x−3)=0 and comment on the nature of its roots.
(iv) The quadratic equation x2+px+9=0 has equal real roots. Find the value of p and write the equation as the square of a single binomial.