momoy momoy 28-05-2017 Mathematics contestada I need some help on 2 questions please? 1. Which trinomials are perfect square trinomials? Select all correct answers. a^2+15a+75 a^2+14a+49 a^2+4a+16 a^2+26a+169 2. Which expressions are differences of squares? a^2-36 x^2+25 n^2-50 w^2-121