(iv)
2x2−x+18=18(16x2−8x+1)
(Splitting the middle term -8x as -4x-4x because −4x×−4x=16x2)
=18(16x2−4x−4x+1)=18(4x(4x−1)−1(4x−1))=18(4x−1)2
Roots of this equation are the values for which (4x−1)2=0
∴(4x−1)=0
⇒x=14
So both the roots of the equation is 14