Correct option is B
Given:
4x2+9y2+16z2−6xy+12yz+8zx8x3+27y3−64z3+72xyz
Formula Used:
Identity:
a3+b3+c3−3abc=(a+b+c)(a2+b2+c2−ab−bc−ca)
Solution:
Let a = 2x, b = 3y, c = -4z.
Numerator:
a3+b3+c3−3abc
=8x3+27y3−64z3+72xyz.
Denominator:
a2+b2+c2−ab−bc−ca
=4x2+9y2+16z2−6xy+12yz+8zx.
Hence the expression becomes
a2+b2+c2−ab−bc−ca(a+b+c)(a2+b2+c2−ab−bc−ca)
= a + b + c
=2x + 3y - 4z.