Question

What is the formulae for (x - y)2?
(i) x2 + xy + y2 (ii) x2+2xy + y2
(iii) x2-2xy+ y2
(iv) x2 - y2​

Answer 1

Step-by-step explanation:

first three terms of the expression is in the form (x+y)

2

and the fourth term is a perfect square.

Hence, x

2

+2xy+y

2

−4z

2

=(x+y)

2

−(2z)

2

=[(x+y)+2z][(x+y)−2z]

=(x+y+2z)(x+y−2z)