Question

Factor completely
a^2-49

Answer 1

Use the difference of two squares factoring.
x^2 - y^2 = (x + y)(x - y)

Answer 2

so then is the answer a(a-7^2)

Answer 3

No.
Follow the pattern.
You start with x^2 - y^2 and you end up with (x + y)(x - y)
In your case you start with a^2 - 49 = a^2 - 7^2, so you end up with
(a + 7)(a - 7)

Answer 4

so the the (a=7)(a-7) is the answer ok I understand thanks.