Which expressions are differences of squares? Select each correct answer.

a^2−36
x^2+25
w^2−121
n^2−50


Which trinomials are perfect square trinomials?

Select each correct answer.

a^2+4a+16

a^2+15a+75

a^2+14a+49

a^2+26a+169



Factor completely.

4p² + 36p + 81

Note: Write the answer in the form: (ap+b)^2