Question

on my test last night i missed only questions where its the diffrence of 2 squares can someone explain to me what that means

Answer 1

an example is
x^2 - 9

x^2 and 9 are 2 perfect squares

to factor this you take the square root of each and plug these into standard form which is

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

Answer 2

so to factor x^2 - 9 - sq roots are x and 3:

= (x - 3)( x + 3)