Consider the three quadratic equations given below.
(i) x2−9x+18=0 : State whether this equation is readily factorisable over integers and give a brief reason for your answer.
(ii) 2x2+7x+3=0 : State whether this equation is readily factorisable over integers and give a brief reason for your answer.
(iii) 3x2−2x+7=0 : State whether this equation is readily factorisable over integers and give a brief reason for your answer.
(iv) For each equation in parts (i)–(iii), identify the solution method you would choose first in an examination to obtain its roots quickly, and justify your choice in not more than two sentences per equation.