Solve for x. Show your work.

Answer:

a) x* e∧ t/10  =  20 *e∧ t/10 + 2

b) x  =  14,2 gall. In 10 min. we get 14,2 gallons of bleach in the tank

c) After a very long time we will find 20 gallons of bleach in the tank

Step-by-step explanation:

The variation of bleach in water in the tank is Δ(x)t:

Δ(x)t  = [Amount of x added to the tank - Amount of x drain out of the tank]*Δt

Now the amount of x added to the tank is:

Rate of adding* the concentration

Rate of adding =  4 gallons per minute

Concentration  half and half ( water + bleach)  = 0,5

Rate of draining =  4 gallons per minute

Concentration of draining: Unknown but can be expressed as:

x(t)/40. According to this

Δ(x)t  =  [4 * 0,5  -  4 * x(t)/40]*Δt

Dividing by Δt on both sides of the equation and tacking limits we get

dx/ dt    =  2  - x / 10

dx/dt + x/10 =2

Multyiplying by e∧ t/10 on both sides

e∧ t/10* [ dx/dt  +  x/10 ]  =  2 *e∧ t/10

To solve it, integrating the first member is

x* e∧ t/10  =  20 *e∧ t/10 + C

for initial condition t = 0

4    =  20 + C

C = -16

a) x* e∧ t/10  =  20 *e∧ t/10 - 16

b) in 10 minutes

x* e∧ t/10  =  20 *e∧ t/10 - 16

x *e  =  20*e  - 16

x   =   20  -  16/e

x   =  20  -  16/2,718

x   =   20 -  5,88

x  =  14,2  gallons.

c) After a very long time we will find 20 gallons of bleach in the tank

Answer:

Area of the figure = 25 square units

Step-by-step explanation:

Area of the given figure = Area of ΔCDE + Area of rectangle BCEI + Area of ΔABH + Area of GIF

Area of ΔCDE = [tex]\frac{1}{2}(\text{Base})(\text{Height})[/tex]

                       = [tex]\frac{1}{2}(CE)(DK)[/tex]

                       = [tex]\frac{1}{2}(8)(4)[/tex]

                       = 16 units²

Area of rectangle BCEI = Length × Width

                                      = CE × EI

                                      = 8 × 1

                                      = 8 units²

Area of ΔABH = Area of ΔGIF = [tex]\frac{1}{2}(1)(1)[/tex]

                                                 = [tex]\frac{1}{2}[/tex] units²

Area of the complete figure = 16 + 8 + [tex]\frac{1}{2}[/tex] + [tex]\frac{1}{2}[/tex]

                                               = 25 units²

Answer:

x=√154 over 7 , −√154 over 7

Step-by-step explanation:

Answer:

the answer is that x=positive or negative square root of 22 over square root of 7

Step-by-step explanation:

Step-by-step explanation:

[tex] \binom{ \lim}{x→0} ( \frac{1}{x} - \frac{1}{ \ \: sinx} ) = \binom{ \lim}{x→0}( \frac{ \ sinx - x }{x \ sinx } ) = \binom{ \lim}{x→0}( \frac{ \ cosx - 1 }{x \ cosx + \ sinx } ) = \frac{0}{0} = 0[/tex]

Answer:

Brainiest please

Step-by-step explanation:

In finance, the rule of 72, the rule of 70 and the rule of 69.3 are methods for estimating an investment's doubling time. The rule number (e.g., 72) is divided by the interest percentage per period (usually years) to obtain the approximate number of periods required for doubling. Although scientific calculators and spreadsheet programs have functions to find the accurate doubling time, the rules are useful for mental calculations and when only a basic calculator is available.

Answer: 3¼ hours

Step-by-step explanation:

Number of hours used in baking = 2¾ hours

Number of hours used in cleaning up the kitchen = ½ hour

Therefore, the time used in the kitchen will be the addition of the time used in baking plus the time used in cleaning the kitchen which will be:

= 2¾ + ½

= 2 3/4 + 2/4

= 2 5/4

= 2 + 1¼

= 3¼ hours

Therefore, 3¼ hours was used in the kitchen.

Answer:

Hello! answer: 4/5

Step-by-step explanation:

20 ÷ 5 = 4 25 ÷ 5 = 5 that is 4/5 therefore 4/5 is the answer because we cannot reduce any further HOPE THAT HELPS!

Answer:

         [tex]\frac{20}{25} =\frac{4}{5}[/tex]

Answer:

12 + 5X = Y

Step-by-step explanation:

Given that a video store charges $ 5 per game rental plus $ 12 to rent the game system, to write an expression for renting the game system and a number of games the following logical reasoning must be performed:

5 = variable not fixed, depends on the number of games

12 = fixed variable

X = number of games

Y = total value

12 + 5X = Y

Thus, if 5 video games were rented, the equation would operate as follows:

12 + 5x5 = Y

12 + 25 = Y

37 = Y

Answer:

-15

Step-by-step explanation:

When m=3 and n=-4

So, put the values

7(3)+3(3)(-4)

-> -15

Answer:

-15

Step-by-step explanation:

= 7(3) + 3(3)(-4)

= 21 + 3(3×-4)

= 21 + 3(-12)

= 21 + -36

= 21-36

= -15

Answer:

27,29

Step-by-step explanation:

Answer:

[tex]I =\frac{P*R*T}{100} = \frac{10000 * 11 * T}{100} = 1100T[/tex]

Given A =20000

[tex]Amount = Interest + Principal\\20000 = 1100T + 10000\\20000 - 10000 = 1100T\\\\T= \frac{10000}{1100} = \frac{100}{11} = 9.09 years[/tex]

T =9years

Answer:

the other angle equal 52

we can use the specail trangle 3 4 5

300 400 500

the 38 degrees angle meet 300

and the 52 degrees angle meet 400

so the answer is 300 i dont know if you understand but i hope you are

pls ask in the comments and i will try to explain because my ebgilish the baddest

I'm still doing the rest but number 1 is D

Answer:

153:20

Step-by-step explanation:

765000/100000

=153/20

Answer:

3×+9=5x-5

-2×=-14

×=7...thenCD=3(7)+9=30

Answer:m

Step-by-step explanation:

Answer:

(3,6)

Step-by-step explanation:

Using the midpoint segment formula

M(X, Y) = [(ax1+bx2/2, ay1+by2/2)]

Given (-2 -6) and (4,6) divided in the ratio 1:5

X = 1(-2) + 5(4)/1+5

X = -2+20/6

X = 18/6

X = 3

Similarly

Y = 1(-6)+ 5(6)/1+5

Y = -6+30/6

Y = 24/6

Y = 4

Hence the required coordinate of C is (3,6)

Answer:

3. B

4. B

5. C

Step-by-step explanation:

Answer:

x > [tex]\frac{1}{5}[/tex]

Step-by-step explanation:

[tex]\frac{5(9-x)}{3+1}<11[/tex]

Add 3 and 1 to get 4.

[tex]\frac{5(9-x)}{4}<11[/tex]

Use the distributive property to multiply 5 by 9−x.

[tex]\frac{45-5x}{4}<11[/tex]

Subtract  45/5 from both sides.

[tex]-\frac{5}{4}x<11-\frac{45}{4}[/tex]

Since 44/4 and 45/4 have the same denominator, subtract them by subtracting their numerators.

[tex]-\frac{5}{4} x<-\frac{1}{4}[/tex]

Multiply both sides by -4/5, the reciprocal of -5/4. Since -5/4 is negative, the inequality direction is changed.

[tex]x>-\frac{1}{4} (-\frac{4}{5} )[/tex]

Multiply -1/4 times -4/5 by multiplying numerator times numerator and denominator times denominator.

[tex]x>\frac{-(-4)}{4 x 5}[/tex]

[tex]x>\frac{1}{5}[/tex]

Answer:

The 95% confidence interval estimate of the population mean  is (7.38, 8.46).

Step-by-step explanation:

Before building the confidence interval, we need to find the mean and standard deviation of the sample.

In this sample, there are 50 values.

Mean of the sample:

Sum of all values divided by the number of values.

With the help of a calculator, the mean is of 7.92.

Standard deviation:

Square root of the division of the sum of the difference squared between each value and the mean by the number of the values.

With the help of a calculator, the standard deviation is of 1.8958.

Confidence interval:

We have the confidence interval for the sample, which means that the t-distribution is used to solve this question.

The first step to solve this problem is finding how many degrees of freedom, we have. This is the sample size subtracted by 1. So

df = 50 - 1 = 49

95% confidence interval

Now, we have to find a value of T, which is found looking at the t table, with 49 degrees of freedom(y-axis) and a confidence level of [tex]1 - \frac{1 - 0.95}{2} = 0.975[/tex]. So we have T = 2.01

The margin of error is:

[tex]M = T\frac{s}{\sqrt{n}} = 2.01\frac{1.8958}{\sqrt{50}} = 0.54[/tex]

In which s is the standard deviation of the sample and n is the size of the sample.

The lower end of the interval is the sample mean subtracted by M. So it is 7.92 - 0.54 = 7.38

The upper end of the interval is the sample mean added to M. So it is 7.92 + 0.54 = 8.46

The 95% confidence interval estimate of the population mean  is (7.38, 8.46).

Answer:

the correct answer is 1ft

Step-by-step explanation:

4ft-3ft

=1ft

Answer:

First point: -4 on y axis.

Second point: (2, -5)

Step-by-step explanation:

When graphing, we always set the equation as y=mx+b where m = slope and b = y intercept

y = mx + b

y = [tex]-\frac{1}{2}x-4[/tex]  

Then we plot by starting with the y intercept going four units down, one unit below and two units to the right.

Answer:

is it 120

Step-by-step explanation:

it is 120 I can't really explain how I got it though

Answer:

31

Step-by-step explanation:

Let the missing angle be x.

Sum of angles in a triangle is supplementary,

x + 20 + 129 = 180

x + 149 = 180

x = 180 - 149

x = 31

Answer:

31

Step-by-step explanation:

A triangle is 180 degrees.

129 + 20 = 149

180 - 49 = 33

Answer:

MK bisects <LKN

Step-by-step explanation:

We can already say two sets of sides are equal; LK = NK because it is given and MK = MK because of reflexive property. In order to use Side-Angle-Side, we need to prove the angles between the sides are congruent. This means <LKM and <NKM. The only option that would help is with the is the lat option, MK bisects <LKN because, then we could say <LKM and NKM are congruent because MK would be an angle bisector. This is exactly what we want, so the answer is MK bisects <LKN.

Answer:

here,radius =2 in

now use formula pie (r)^2 where pie is 3.14

=pie *(r)^2

=3.14*(2in.)^2

=3.14*4in.^2

12.56in.^2

Step-by-step explanation: