Which expressions are perfect square trinomials? Check all that apply.
a.x2 + 16x + 8
b.x2 + 14x + 49
c.x2 – 5x + 25
d.x2 – 24x + 144
e.x2 + 9x – 81
a.x2 + 16x + 8
b.x2 + 14x + 49
c.x2 – 5x + 25
d.x2 – 24x + 144
e.x2 + 9x – 81