Answer:
[tex]\boxed{(a-y) (b - y)}[/tex]
Step-by-step explanation:
Rearrange the terms.
[tex](ab - ay) (-by + y^2)[/tex]
Factor out common term.
[tex]a (b - y) -y ( b - y)[/tex]
Apply rule : [tex]a(b+c)+d(b + c) = (a+d)(b+c)[/tex]
[tex]a (b +- y) +-y ( b +- y)[/tex]
[tex](a+-y) (b +- y)[/tex]
