<span>h = -8t² + 40t
dh/dt = 0
⇒ d/dt(</span><span>-8t² + 40t) = 0
⇒ -16t + 40 = 0
⇒ 16t = 40
⇒ t = 40/16 = 2.5s
So it takes 2.5 seconds to reach highest point
h = -8×2.5² + 40×2.5 = -50 + 100 = 50
Ordered pair: (h,t) = (50,2.5)
</span>
Answer:
Russell family's sprinkler: 40 hours
Gonzales family's sprinkler: 20 hours
Step-by-step explanation:
Let's call the amount of time the Russell family's sprinkler was on by X, and the Gonzales family's sprinkler by Y.
We can then formulate the equations:
X + Y = 60
X*35 + Y*40 = 2200
We can solve this system multiplying the first equation by 35, and then subtracting the result from the second equation:
35*X + 35*Y = 2100
5*Y = 100
Y = 20
from the first equation:
X + 20 = 60
X = 40
Russell family's sprinkler: 40 hours
Gonzales family's sprinkler: 20 hours
I did it on the calculator and the answer is 7.77777777778
Answer:
uhhhhhhhhhhhhhhhhhhhhhhh
Step-by-step explanation:
