Since the formula for .
So,
= (Breaking -2xy as -xy-xy)
= (Making the group of terms)
=x(x-y) +y(y-x)-a(y-x) (Taking out the common factor)
=-x(y-x)+y(y-x)-a(y-x)
=(y-x)(-x+y-a)
=-(x-y)(-(x-y+a))
=(x-y)(x-y+a)
6.5m questions
8.6m answers