Factorise:
(x2+1x2)−4(x+1x)+6
(x2+1x2)−4(x+1x)+6⇒(x2+1x2+2)−4(x+1x)+4⇒(x+1x)2−2×2(x+1x)+(2)2=(x+1x−2)2{∵a2−2ab+b2=(a−b)2}
Factories: (x2−4x)(x2−4x−1)−20
Factorise x2 + x/6 -1/6