Answer:
either it's 1:3 or 1:6
Step-by-step explanation:
3 students went to the zoo, and 15 students went to the aquarium.
15 plus 3 is 18.
3/18 then reduces to 1/6
therefore it is:
1:6
(before, I got my answer deleted so, maybe it is 1:3, but I solved it and got 1:6)
First you solve 2y-3y=9.

Now that you have y, then you substitute y into x-2y=3 to find X

Your solution is (-15, -9)
Your problem statement needs a bit of correction:
"<span>Y= -16t^2 +400, where t represents the number OF SECONDS after the camera is dropped. How long will it BE before Kay sees the splash from the camera hitting the water?"
Set y = -16t^2 + 400 = 0. We assume that 400 and 0 represent feet (English system).
Then 16t^2 = 400, and so 25 = t^2. Only the positive square root makes sense here, and that root is 5 (seconds).</span>
They need 18 more teachers.
Set the problem up as a ratio.
3 x
---- = -------
70 14,700
70 x = 44,100
x = 630
The district already has 612 teachers. So, 630 - 612 = 18 more needed.