Factorisation and equation solving.
(i) For the quadratic polynomial 20x2−3x−35, list all ordered pairs of integers whose product equals the value of ac.
(ii) Select a suitable pair from part (i) to rewrite the middle term and hence factor 20x2−3x−35 completely.
(iii) Using your factorisation, solve the quadratic equation 20x2−3x−35=0.
(iv) Substitute each root obtained in part (iii) back into the original equation to verify your solutions.