Given that the volume of water remaining in the tank after t minutes is given by the function

where V is in gallons, 0 ≤ t ≤ 20 is in minutes, and t = 0 represents the instant the tank starts draining.
The rate at which water is draining four and a half minutes after it begins is given by
![\left. \frac{dV}{dt} \right|_{t=4 \frac{1}{2} = \frac{9}{2} }=\left[40,000\left(1- \frac{t}{20} \right)\left(- \frac{1}{20} \right)\right]_{t= \frac{9}{2} } \\ \\ =\left[-2,000\left(1- \frac{t}{20} \right)\right]_{t= \frac{9}{2} }=-2,000\left(1- \frac{4.5}{20} \right) \\ \\ =-2,000(1-0.225)=-2,000(0.775)=-1,550\, gallons\ per\ minute](https://tex.z-dn.net/?f=%5Cleft.%0A%20%5Cfrac%7BdV%7D%7Bdt%7D%20%5Cright%7C_%7Bt%3D4%20%5Cfrac%7B1%7D%7B2%7D%20%3D%20%5Cfrac%7B9%7D%7B2%7D%20%0A%7D%3D%5Cleft%5B40%2C000%5Cleft%281-%20%5Cfrac%7Bt%7D%7B20%7D%20%5Cright%29%5Cleft%28-%20%5Cfrac%7B1%7D%7B20%7D%20%0A%5Cright%29%5Cright%5D_%7Bt%3D%20%5Cfrac%7B9%7D%7B2%7D%20%7D%20%5C%5C%20%20%5C%5C%20%3D%5Cleft%5B-2%2C000%5Cleft%281-%20%0A%5Cfrac%7Bt%7D%7B20%7D%20%5Cright%29%5Cright%5D_%7Bt%3D%20%5Cfrac%7B9%7D%7B2%7D%20%7D%3D-2%2C000%5Cleft%281-%20%0A%5Cfrac%7B4.5%7D%7B20%7D%20%5Cright%29%20%5C%5C%20%20%5C%5C%20%3D-2%2C000%281-0.225%29%3D-2%2C000%280.775%29%3D-1%2C550%5C%2C%20%0Agallons%5C%20per%5C%20minute)
Therefore, the water is draining at a rate of 1,550 gallons per minute four ans a half minutes after it begins.
Answer option E is the correct answer.
I don’t know guat your sayin my friend my bad
(i) I used distributive property to get the x’s and y’s out of parentheses. I then combined like-terms to simplify until I could do no more. That is your final answer for (i) is -3x - 12y
(ii) This one is similar to the first one, just with no parentheses. I combined like terms again until not like terms were left. Your final answer for (ii) is -3k -2 -2n
(iii) I started by dividing 15 by 3 and got 5, and because the 15 had an x to it, you get 5x. I then moved onto the next term, 9. 9 divided by 3, to get 3. Your final answer for (iii) is 5x + 3
What is the interquartile range of this data set?<br>
2,5,9,11,18, 30, 42, 48, 55, 73, 81
Lubov Fominskaja [6]
Answer:
46
Step-by-step explanation:
55-9=46
2=min
9=Lq
30=median
55= Uq
81= max
Answer:
(x - 1) and (x + 4)
Step-by-step explanation:
Given the zeros of a polynomial, say x = a, x = b then the factors are
(x - a), (x - b) and the polynomial is the product of the factors, that is
f(x) = (x - a)(x - b)
Here the zeros are x = 1 and x = - 4, thus the factors are
(x - 1) and (x - (- 4)), that is (x - 1) and (x + 4)