Answer:
a²x² + a²y² + b²x² + b²y²
Step-by-step explanation:
firstly lets expand the first part of the expression
using the formula (a + b)² = a²+ 2ab +b²
(ax + by)² = a²x² + 2axby + b²y²
secondly lets expand the other part using the formula (a - b)² = a² - 2ab +b²
(bx - ay)² = b²x² - 2bxay + a²y²
and lastly lets sum it up
a²x² + 2axby + b²y² + b²x² - 2bxay + a²y²
as we can see from this expanded form of expression we can remove 2axby - 2axby
which gives us the answer
a²x² + a²y² + b²x² + b²y²