Well, without even looking at it, I can say it's a downwards facing parabola, which roots at x = -3 and x = 5. That should do it.
(x-5)(x+4) is the factored version of this trinomial so if either of those values in the parenthesis are in the answer bank, choose those.
Answer: 39 students.
Step-by-step explanation: 1/5 of 75 is 60. Now we need to find out what 3/5 of 60 is. 3/5 times 60 = 39. 39 students need to give their speeches.