Tick (✓) the correct answer: x2 − xz + xy − yz = ? (a) (x − y)(x + z) (b) (x − y)(x − z) (c) (x + y)(x − z) (d) (x − y)(z − x)
x2−xz+xy−yz=?(a) (x−y)(x+z)(b) (x−y)(x−z)(c) (x+y)(x−z)(d) (x−y)(z−x)
If x,y,z∈R+ then xyx+y+yzy+z+xzx+z is always