Pls answer ASAP!! due 6:00 pm on 9/25/2020, but I would really appreciate a late reply too. pls answer, will give 25 points and brainiest!

Replace ∗ with a monomial so that the trinomial may be represented by a square of a binomial:

a) ∗ +28a+49
b) 36–24x + ∗
c) 6.25a^2 + ∗ + 1/4 b^2
d)∗ +2bc+100c^2

Thank you so much if you answered. I tried a lot, but couldn't get. PLEASE SHOW YOUR WORK I REALLY DONT GET IT!! ;-;