What are the solutions to 2x squared +7x=4

9 is the geometric mean between 4 and which other number?

KonstantinChe [14]

Answer is A. 20.25

cause 20.25 x 9 = 81
√81 = 9
so 9 is the geometric mean between 4 and 20.25

5 0

4 years ago

A 100 gallon tank initially contains 100 gallons of sugar water at a concentration of 0.25 pounds of sugar per gallon suppose th

Vsevolod [243]

At the start, the tank contains

(0.25 lb/gal) * (100 gal) = 25 lb

of sugar. Let $S(t)$ be the amount of sugar in the tank at time $t$ . Then $S(0)=25$ .

Sugar is added to the tank at a rate of P lb/min, and removed at a rate of

$\left(1\frac{\rm gal}{\rm min}\right)\left(\dfrac{S(t)}{100}\dfrac{\rm lb}{\rm gal}\right)=\dfrac{S(t)}{100}\dfrac{\rm lb}{\rm min}$

and so the amount of sugar in the tank changes at a net rate according to the separable differential equation,

$\dfrac{\mathrm dS}{\mathrm dt}=P-\dfrac S{100}$

Separate variables, integrate, and solve for S.

$\dfrac{\mathrm dS}{P-\frac S{100}}=\mathrm dt$

$\displaystyle\int\dfrac{\mathrm dS}{P-\frac S{100}}=\int\mathrm dt$

$-100\ln\left|P-\dfrac S{100}\right|=t+C$

$\ln\left|P-\dfrac S{100}\right|=-100t-100C=C-100t$

$P-\dfrac S{100}=e^{C-100t}=e^Ce^{-100t}=Ce^{-100t}$

$\dfrac S{100}=P-Ce^{-100t}$

$S(t)=100P-100Ce^{-100t}=100P-Ce^{-100t}$

Use the initial value to solve for C :

$S(0)=25\implies 25=100P-C\implies C=100P-25$

$\implies S(t)=100P-(100P-25)e^{-100t}$

The solution is being drained at a constant rate of 1 gal/min; there will be 5 gal of solution remaining after time

$1000\,\mathrm{gal}+\left(-1\dfrac{\rm gal}{\rm min}\right)t=5\,\mathrm{gal}\implies t=995\,\mathrm{min}$

has passed. At this time, we want the tank to contain

(0.5 lb/gal) * (5 gal) = 2.5 lb

of sugar, so we pick P such that

$S(995)=100P-(100P-25)e^{-99,500}=2.5\implies\boxed{P\approx0.025}$

5 0

3 years ago

Here is a five-sided polygon. Describe or show the strategy you would use to find its area. Mark up and label the diagram to sho

MrRissso [65]

Answer:

i can explai it to u if u wan to get the answer

Step-by-step explanation:

Divide the polygon into 5 triangles by using each side as a base and joining the vertices of the polygon to a common point (for example, the centre). If the polygon is regular the angle at the vertex of each triangle is 360/5=72 degrees, so you have 5 isosceles triangles of equal area. Find the area of one and multiply by 5 to get the total area.multiply 5 times the lenght of oneside

6 0

4 years ago

PLEASE HELP ME QUICK PLEEEEAAASE

sasho [114]

Answer:

A 2/6 and 3/6 is the Answer

7 0

3 years ago

Read 2 more answers

A recipe calls for gallon of punch, 3 pints of club soda, and 2 cups of ice cream.

Finger [1]

The answer to your question is 4 quarts