Question

Factorise

X square-y square-2x+6y-8

Answer 1

instead of -8 write -9 + 1

x^2 - y^2 - 2x + 6y - 9 + 1 =

x^2 - 2x + 1 - y^2 + 6y - 9 =

x^2 - 2x + 1 - (y^2 - 6y + 9) =

(x - 1)^2 - (y - 3)^2 =

(x-1 + y-3)(x-1 - (y-3)) = (x + y - 4)(x - y + 2)