Practice problem
Which of the following, when expanded, would give a perfect square trinomial?
(x+y)(x−y)(x + y)(x - y)(x+y)(x−y)
(x+y)(x+y)(x + y)(x + y)(x+y)(x+y)
(x+2y)(x−2y)(x + 2y)(x - 2y)(x+2y)(x−2y)
(x−y)(a+b)(x - y)(a + b)(x−y)(a+b)
Type a concept, like “slope” or “photosynthesis”.