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3 years ago

Multiple Choice: Please select the best answer and click "submit."

1 answer:

6 0

The answer is c first 2×6= 12 then 12-5=7
then do -7×-2=14 the minus signs cancel
finaly we have two bracket so we multiply both number (7)×(14)=98

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What is the slope of a l8ne that contains the points (34,12) and (32,48)

Vlad [161]

I hope this helps you

slope (34-32)= 12-48

slope.2= -36

slope = -18

7 0

3 years ago

A 75-gallon tank is filled with brine (water nearly saturated with salt; used as a preservative) holding 11 pounds of salt in so

Debora [2.8K]

Let $A(t)$ = amount of salt (in pounds) in the tank at time $t$ (in minutes). Then $A(0) = 11$ .

Salt flows in at a rate

$\left(0.6\dfrac{\rm lb}{\rm gal}\right) \left(3\dfrac{\rm gal}{\rm min}\right) = \dfrac95 \dfrac{\rm lb}{\rm min}$

and flows out at a rate

$\left(\dfrac{A(t)\,\rm lb}{75\,\rm gal + \left(3\frac{\rm gal}{\rm min} - 3.25\frac{\rm gal}{\rm min}\right)t}\right) \left(3.25\dfrac{\rm gal}{\rm min}\right) = \dfrac{13A(t)}{300-t} \dfrac{\rm lb}{\rm min}$

where 4 quarts = 1 gallon so 13 quarts = 3.25 gallon.

Then the net rate of salt flow is given by the differential equation

$\dfrac{dA}{dt} = \dfrac95 - \dfrac{13A}{300-t}$

which I'll solve with the integrating factor method.

$\dfrac{dA}{dt} + \dfrac{13}{300-t} A = \dfrac95$

$-\dfrac1{(300-t)^{13}} \dfrac{dA}{dt} - \dfrac{13}{(300-t)^{14}} A = -\dfrac9{5(300-t)^{13}}$

$\dfrac d{dt} \left(-\dfrac1{(300-t)^{13}} A\right) = -\dfrac9{5(300-t)^{13}}$

Integrate both sides. By the fundamental theorem of calculus,

$\displaystyle -\dfrac1{(300-t)^{13}} A = -\dfrac1{(300-t)^{13}} A\bigg|_{t=0} - \frac95 \int_0^t \frac{du}{(300-u)^{13}}$

$\displaystyle -\dfrac1{(300-t)^{13}} A = -\dfrac{11}{300^{13}} - \frac95 \times \dfrac1{12} \left(\frac1{(300-t)^{12}} - \frac1{300^{12}}\right)$

$\displaystyle -\dfrac1{(300-t)^{13}} A = \dfrac{34}{300^{13}} - \frac3{20}\frac1{(300-t)^{12}}$

$\displaystyle A = \frac3{20} (300-t) - \dfrac{34}{300^{13}}(300-t)^{13}$

$\displaystyle A = 45 \left(1 - \frac t{300}\right) - 34 \left(1 - \frac t{300}\right)^{13}$

After 1 hour = 60 minutes, the tank will contain

$A(60) = 45 \left(1 - \dfrac {60}{300}\right) - 34 \left(1 - \dfrac {60}{300}\right)^{13} = 45\left(\dfrac45\right) - 34 \left(\dfrac45\right)^{13} \approx 34.131$

pounds of salt.

7 0

2 years ago

Write the number ofhundreds, tens, and ones.

otez555 [7]

Answer:100 10 1

Step-by-step explanation:

4 0

3 years ago

5*9 (sqrt 10)^3= Help please

Nikitich [7]

Use BODMAS or BIDMAS (Brackets, over Indices, Division, Multiplication, Addition, the Subtraction, this tells you which order to do things in)

As you cant do √10 in the brackets you do the indices, so (√10)³
Split this up to make it easier
(√10)³= √10 x √10 x √10 = 10√10

You the multiply this by 9

9 x 10√10 = 90√10

then multiply by 5

5 x 90√10 = 450√10 = 1423.024947 (using calculator)

7 0

3 years ago

Identify 11 as either rational or irrational, and approximate to the tenths place. a.Rational:/(11)~3.3

inysia [295]

I think your answer is c but I'm not sure

8 0

3 years ago