You forgot to include the options. This might help, though.
Answer:
76,
Step-by-step explanation:
If you divide 57 by 3, you get 19. If you times 19 by 4 that is the total number of students there were in all.
Answer:
4r² - 5r - 15 / r(r+3)
Step-by-step explanation:
To solve this problem, we will proceed the following way, writing down the common multiple of the denominators.

Thus, the answer is 4r² - 5r - 15 / r(r+3)
What are you trying to do here?
Solve the graph, or make it appear as something else?
First, we're going to take one sec (x) out so that we get:
sec (x) (2sec (x) -1 -1) = 0
sec (x) (2sec (x) -2) = 0
Then we're going to separate the two to find the zeros of each because anything time 0 is zero.
sec(x) = 0
2sec (x) - 2 = 0
Now, let's simplify the second one as the first one is already.
Add 2 to both sides:
2sec (x) = 2
Divide by 3 on both sides:
sec (x) = 1
I forgot my unit circle, so you'd have to do that by yourself. Hopefully, I helped a bit though!