Factorize each of the following expressions:

a²x² + b²y² + 2axby + b²x² + a²y² – 2axby

= a² (x² + y²) + b² (x² + y²)

= (a² + b²) (x² + y²)

14

15

Factorize each of the following expressions:

17

Factorize each of the following expressions:

18

Factorize each of the following expressions: