Answer:
c) Trinomial Seeing Structure (Substitution method)
Explanation:
The initial expression is
(a + b)² - (a + b) - 6
So, if we replace (a+b) by x, we get:
x² - x - 6
Now, we can factorize it by finding two numbers that multiply to -6 and add to -1. These numbers are -3 and 2, so it is equal to
(x - 3)(x + 2)
Finally, we can replace x = a + b, so
(a + b - 3)(a + b + 2)
The expression x² - x - 6 looks like a trinomial. It means that the best method for the given expression is
c) Trinomial Seeing Structure (substitution method)