How do I factor each polynomial, using gcf: 3p^2-75?

First factor out the common 3 from both terms:
3(p² - 25)

Now use the difference of squares factoring --> a² - b² = (a - b)(a + b)
a = p
b = 5

Answer:
3(p - 5)(p + 5)

3 [ p² - 25 ]

3 [ p - 5 ] [ p + 5 ]

3p^2-75 = 0

3 p ^ 2 = 75

p ^ 2 = 25

p = 5 , - 5

(p + 5) (p - 5)

3(p^2 - 5^2)
= 3(p + 5)(p - 5)

3p^2 - 75 =

3(p^2 - 25) =

3(p - 5)(p + 5)

a^2 - b^2 = (a-b)(a+b)