Answer:
a² - 49
Step-by-step explanation:
(a + 7)(a - 7) = ?
This is what we call us the difference of two squares.
Initially, a² - b² is written as (a + b)(a - b)
So the solution to (a + 7)(a - 7) is a² - 7²
That gives a² - 49
Answer:
Step-by-step explanation:
Use (a + b)(a - b) = a² - b²:
(a + 7)(a - 7) = a² - 7² = a² - 49
Other method:
Use FOIL: (a + b)(c + d) = ac + ad + bc + bd:
(a + 7)(a - 7) = (a)(a) + (a)(-7) + (7)(a) + (7)(-7) = a² - 7a + 7a - 49 = a² - 49
