Use the identity (x+a)(x+b)=x2+(a+b)x+ab to find the following products: (abc−4)(abc−2)
a2b2c2−6abc−8
a2b2c2−6abc+8
a2b2c2+6a+8
a2b2c2−6a−8
⇒(abc−4)(abc−2) =(abc)2+(−4−2)×abc+(−4)×(−2) [Using identity(x+a)(x+b)=x2+(a+b).x+ab] =a2b2c2−6abc+8