Answer:
The highest common factor is (a + b)
Step-by-step explanation:
We start by making a factorization of the first expression
By using the difference of two squares, we can have it as;
a^2 - b^2 = (a + b)(a-b)
For the second expression, we already have;
(a + b)^2 = (a + b)(a + b)
What this mean is that (a + b) is common to both expressions and we have it as the highest common factor
