Omg plz help with this question

also this question is a bit diffucult- will i need to plug in some number in for x to figure out which answer choice is correct?

Guest Mar 22, 2019

#1**0 **

First equation gives the input RATE.....second equation gives the output RATE

first equation - second equation = net input rate (like how much is filling the tub)

(3) will tell you the NET RATE of tank filling at 3 hr

3(3^2)+2 - (4(3)-1 )=

29 - 11 = 18 After 3 hours THE FILLING RATE is 18 gallons/hr

ElectricPavlov Mar 22, 2019

edited by
ElectricPavlov
Mar 22, 2019

edited by ElectricPavlov Mar 22, 2019

edited by ElectricPavlov Mar 22, 2019

edited by ElectricPavlov Mar 22, 2019

edited by ElectricPavlov Mar 22, 2019

#2**0 **

When debt = 0 f(x) = 0

0 = -4x^2+10x+60 Solve for x

I used quadratic formula

\(x = {-b \pm \sqrt{b^2-4ac} \over 2a}\) with a = -4 b = 10 c = 60 to find x = -2.82 and 5.32 (throw out the negative) 5.3 years

ElectricPavlov Mar 22, 2019

#5**0 **

Ok thx, & you said the answer for the second question is 5.3?

Guest Mar 22, 2019

edited by
Guest
Mar 22, 2019

edited by Guest Mar 22, 2019

edited by Guest Mar 22, 2019

edited by Guest Mar 22, 2019

edited by Guest Mar 22, 2019

#6

#8**0 **

( i - d)(3) is the rate at which the volume of liquid is changhing at 3 hrs....to find this we have

[ 3(3)^2 + 2 ] - [ 4(3) - 1 ] =

[ 27 + 2 ] - [11[ =

29 - 11 =

18 gal per hour (third answer )

Next one

We want to find when the debt = 0 .....so.....

-4x^2 + 10x + 60 = 0 divide through by - 2

2x ^2 - 5x - 30 = 0

The graph here shows that the company will get out of debt after about 5.3 years

https://www.desmos.com/calculator/rtundu47as

CPhill Mar 23, 2019