Step-by-step explanation:
[tex](a - b)(a + b) = {a}^{2} - {b}^{2} [/tex]
simplify the product and you get
[tex] {1}^{2} - (3p {}) {}^{2} [/tex]
1 times any power automatically equals 1. So that equals
[tex]1 - (3p) {}^{2} [/tex]
=
[tex]1 - 9p {}^{2} [/tex]
