S<span>tep-1 : Multiply the coefficient of the first term by the constant </span><span> <span> 3</span> • 4 = 12</span>
<span>Step-2 : Find two factors of </span> 12 <span> whose sum equals the coefficient of the middle term, which is </span><span> 13 </span><span>. </span><span><span>