By definition we have to:
Difference of squares of two terms is equal to the product of the sum of these terms by the difference of these terms:
[tex]a ^ 2 - b ^ 2 = (a + b) (a - b)
[/tex]
We then have the following expression:
[tex]y^ 2-225
[/tex]
Rewriting we have:
[tex]y^ 2-15 ^ 2
[/tex]
Using the definition, we have to:
[tex]y ^ 2-15 ^ 2 = (y-15) * (y + 15)
[/tex]
Answer:
B: is a difference of squares: (y-15)(y+15)
