Question

factorise: x2-y2-2x+6y-8

Answer 1

2x-2y-2x+6y-8
=2x-2x-2y+6y-8
=4y-8
=4(y-2)

Answer 2

x²-2x -y²+6y -8

=x²-2x +1 -y² +6y -9

=(x+1)² - (y² -6y +3²)

=(x-1)²-(y-3)²

=[(x-1) + (y-3)][(x-1) - (y-3)]

=(x+y-4)(x-y+2)