which expression shows a way to find 2813×7

(a) Take the Laplace transform of both sides:

[tex]2y''(t)+ty'(t)-2y(t)=14[/tex]

[tex]\implies 2(s^2Y(s)-sy(0)-y'(0))-(Y(s)+sY'(s))-2Y(s)=\dfrac{14}s[/tex]

where the transform of [tex]ty'(t)[/tex] comes from

[tex]L[ty'(t)]=-(L[y'(t)])'=-(sY(s)-y(0))'=-Y(s)-sY'(s)[/tex]

This yields the linear ODE,

[tex]-sY'(s)+(2s^2-3)Y(s)=\dfrac{14}s[/tex]

Divides both sides by [tex]-s[/tex]:

[tex]Y'(s)+\dfrac{3-2s^2}sY(s)=-\dfrac{14}{s^2}[/tex]

Find the integrating factor:

[tex]\displaystyle\int\frac{3-2s^2}s\,\mathrm ds=3\ln|s|-s^2+C[/tex]

Multiply both sides of the ODE by [tex]e^{3\ln|s|-s^2}=s^3e^{-s^2}[/tex]:

[tex]s^3e^{-s^2}Y'(s)+(3s^2-2s^4)e^{-s^2}Y(s)=-14se^{-s^2}[/tex]

The left side condenses into the derivative of a product:

[tex]\left(s^3e^{-s^2}Y(s)\right)'=-14se^{-s^2}[/tex]

Integrate both sides and solve for [tex]Y(s)[/tex]:

[tex]s^3e^{-s^2}Y(s)=7e^{-s^2}+C[/tex]

[tex]Y(s)=\dfrac{7+Ce^{s^2}}{s^3}[/tex]

(b) Taking the inverse transform of both sides gives

[tex]y(t)=\dfrac{7t^2}2+C\,L^{-1}\left[\dfrac{e^{s^2}}{s^3}\right][/tex]

I don't know whether the remaining inverse transform can be resolved, but using the principle of superposition, we know that [tex]\frac{7t^2}2[/tex] is one solution to the original ODE.

[tex]y(t)=\dfrac{7t^2}2\implies y'(t)=7t\implies y''(t)=7[/tex]

Substitute these into the ODE to see everything checks out:

[tex]2\cdot7+t\cdot7t-2\cdot\dfrac{7t^2}2=14[/tex]

Answer:

6.28 m

Step-by-step explanation:

If a wheel travels with one full revolution, it would have travelled the circumference's distance from it's starting point.

The circumference of a circle is [tex]2\pi r[/tex]

Let's assume [tex]\pi[/tex] is 3.14 and solve for the equation.

[tex]2\cdot3.14\cdot1\\6.28[/tex]

Hope this helped!

Answer:

2√2

Step-by-step explanation:

hope you understand.

Answer:

Yes you can

Step-by-step explanation:

To eliminate the denominator

Answer:

No

Step-by-step explanation:

We cannot be certain that x + 3 > 0

If it was negative then the sign of the inequality would change.

To solve find the critical values of the numerator/ denominator, that is

x = 2 and x = - 3

The domain is the split into 3 intervals

(- ∞, - 3 ), (- 3, 2), (2, + ∞ )

Use test points from each interval to determine valid solution

Answer:

Step-by-step explanation:

vector OA=a

vector OB=b

vector OX= λ vector OA=λa

vector OY=μ vector OB=μb

a.

1.vector BX=(vector OX-vector OB)=λa-b

ii. vector AY=(vector OY-vector OA)=μb-a

b.

5 vector BP=2 vector BX

5(vector OP-vector OB)=2 (vector OX-vector OB)

5(vector OP-b)=2(λa-b)

5 vector OP-5b=2λa-2b

5 vector OP=2λa-2b+5b

vector OP=1/5(2λa+3b)

ii

complete it.

Answer:

Find a common denominator on the right side of the equation

Step-by-step explanation:

The equation before the problem is

X² + b/a(x) + (b/2a)²= -c/a + b²/4a²

The next step in solving the above equation is to fibd tge common denominator on the right side of the equation.

X² + b/a(x) + (b/2a)²= -c/a + b²/4a²

X² + b/a(x) + (b/2a)²= -4ac/4a² + b²/4a²

X² + b/a(x) + (b/2a)²=( b²-4ac)/4a²

The right side of the equation now has a common denominator

The next step is to factorize the left side of the equation.

(X+b/2a)²= ( b²-4ac)/4a²

Squaring both sides

X+b/2a= √(b²-4ac)/√4a²

Final equation

X=( -b+√(b²-4ac))/2a

Or

X=( -b-√(b²-4ac))/2a

Answer:

35 or 25

Step-by-step explanation:

Answer:

Paula will travel 234 miles in 4.5 hours

Step-by-step explanation:

Step 1: We first find the speed Paula is going in hours, we divide 130 mile by 2.5 hours to get 52 miles per hour

Step 2: We multiple 52 miles per hour with 4.5 hours to get 234 miles

Therefore Paula will travel 234 miles in 4.5 hours

Answer:

(a) Null Hypothesis, [tex]H_0[/tex] : [tex]\mu \geq[/tex] 30 points

    Alternate Hypothesis, [tex]H_A[/tex] : [tex]\mu[/tex] < 30 points

(b) Type I error is that we conclude that test-takers who had completed the training showed a mean increase smaller than 30 points but in actual, the program raises SAT scores by an average of at least 30 points.

Step-by-step explanation:

We are given that a test-preparation company advertises that its training program raises SAT scores by an average of at least 30 points.

A random sample of test-takers who had completed the training showed a mean increase smaller than 30 points.

Let [tex]\mu[/tex] = average SAT score.

(a) So, Null Hypothesis, [tex]H_0[/tex] : [tex]\mu \geq[/tex] 30 points

Alternate Hypothesis, [tex]H_A[/tex] : [tex]\mu[/tex] < 30 points

Here, the null hypothesis states that the training program raises SAT scores by an average of at least 30 points.

On the other hand, the alternate hypothesis states that test-takers who had completed the training showed a mean increase smaller than 30 points.

(b) Type I error states the probability of rejecting the null hypothesis given the fact that null hypothesis is true.

According to the question, the Type I error is that we conclude that test-takers who had completed the training showed a mean increase smaller than 30 points but in actual, the program raises SAT scores by an average of at least 30 points.

The consequence of a Type I error is that we conclude the test-takers have low SAT scores but in actual they have an SAT score of at least 30 points.

Answer:

B

Step-by-step explanation:

we take the only point we know

(0,20)

in A when x =0

[tex]f(x)=e^{20x} =e^{20*0}=1[/tex]

in B when x=0

[tex]f(x)=20e^x=20e^0=20*1=20[/tex]

fits

in C

[tex]f(x)=20^x=20^0=1[/tex]

in D

[tex]f(x)=20^{20x}=20^{20*0}=20^0=1[/tex]

so the only choice is B

Answer:

No, it's not enough

Step-by-step explanation:

Given

Tilling Dimension = 4m by 2m

Tile Dimension = 400mm by 400mm

Required

Determine the 45 tiles is enough

First;

The area of the tiling has to be calculated

[tex]Area = Length * Breadth[/tex]

[tex]Area = 4m * 2m[/tex]

[tex]Area = 8m^2[/tex]

Next, determine the area of the tile

[tex]Area = Length * Breadth[/tex]

[tex]Area = 400mm * 400mm[/tex]

Convert measurements to metres

[tex]Area = 0.4m* 04m[/tex]

[tex]Area = 0.16\ m^2[/tex]

Next, multiply the above area result by the number of files

[tex]Total = 0.16m^2 * 45[/tex]

[tex]Total = 7.2m^2[/tex]

Compare 7.2 to 8

Hence, we conclude that the 45 tiles of 400mm by 400 mm dimension is not enough to floor his bathroom

=========================================================

Explanation:

The original line has a given slope of -6/13. The opposite reciprocal is 13/6. We flip the fraction and the sign from negative to positive.

With any two perpendicular slopes, they always multiply to -1

(-6/13)*(13/6) = (-6*13)/(13*6) = -78/78 = -1

--------------------

Since the perpendicular slope is 13/6, we need to see which of the four answer choices produces a slope of 13/6. Use the slope formula.

This is something you do through trial and error. You could start with A and work your way to D, or just pick at random. I'll go through each one by one starting at choice A.

---------------------

Let's try choice A

m = (y2 - y1)/(x2 - x1)

m = (2 - (-4))/(-7 - 13)

m = (2 + 4)/(-7 - 13)

m = 6/(-20)

m = -3/10, we can see that choice A is not the answer, since we want m = 13/6 instead.

-----------------------

Let's try choice B

m = (y2 - y1)/(x2 - x1)

m = (2 - (-4))/(-7 - 6)

m = (2 + 4)/(-7 - 6)

m = 6/(-13)

m = -6/13, that doesn't work either

------------------------

Let's try choice C

m = (y2 - y1)/(x2 - x1)

m = (-7 - 6)/(-4 - 2)

m = -13/(-6)

m = 13/6, we found the answer

------------------------

For the sake of completeness, here is what choice D would look like

m = (y2 - y1)/(x2 - x1)

m = (-4 - 9)/(-4 - 6)

m = -13/(-10)

m = 13/10, which isn't the slope we want

Answer:

2.086

Step-by-step explanation:

Log 122 is equal to 2.086

Step-by-step explanation:

or,[(√-x-1)+(√x+9)]^2=4^2

or,(√-x-1)^2+2√(-x-1)(x+9)+(√x+9)^2=16

or,-x-1+2√-x^2-10x-9 +x+9=16

or,2√-x^2-10x-9=8

or,√-x^2-10x-9=4

squaring on both sides

or,-x^2-10x-9=16

or,-x^2-10x=25

or,-x(x+10)=25

Either,

x=-25 or, x=15.

Answer: n is a positive odd number.

Step-by-step explanation:

Ok, we know that the function is something like:

f(x)=a(x+k)^1/n + c

In the graph we can see two thigns:

All the values of the graph are positive values (even for the negative values of x), but in the left side we can see that the function decreases and is different than the right side.

So this is not an even function, then n must be an odd number (n odd allows us to have negative values for y = f(x) that happen when x + k is negative).

Also, we can see that the function increases, if n was a negative number, like: n = -N

we would have:

[tex]f(x) = \frac{a}{(x+k)^{1/N}} + c[/tex]

So in this case x is in the denominator, so as x increases, we would see that the value of y decreases, but that does not happen, so we can conclude that the value of n must be positive.

Then n is a positive odd number.

Answer:

D) Positive Even Integer

Step-by-step explanation:

just did it

Answer:

30% is the correct answer.

Step-by-step explanation:

Total number of boys = 2

Total number of girls = 3

Total number of students = 5

To find:

Probability that the pianist will be a boy and the alternate will be a girl?

Solution:

Here we have to make 2 choices.

1st choice has to be boy (pianist) and 2nd choice has to be girl (alternate).

[tex]\bold{\text{Required probability }= P(\text{boy as pianist first}) \times P(\text{girl as alternate})}[/tex]

Formula for probability of an event E is given as:

[tex]P(E) = \dfrac{\text{Number of favorable cases}}{\text {Total number of cases}}[/tex]

For [tex]P(\text{boy as pianist})[/tex], number of favorable cases are 2 (total number of boys).

Total number of cases = Total number of students i.e. 5

So, [tex]P(\text{boy as pianist})[/tex] is:

[tex]P(\text{boy as pianist}) = \dfrac{2}{5}[/tex]

For [tex]P(\text{girl as alternate})[/tex], number of favorable cases are 3 (total number of girls).

Now, one boy is already chosen as pianist so Total number of cases = Total number of students left i.e. (5 - 1) = 4

[tex]P(\text{girl as alternate}) = \dfrac{3}{4}[/tex]

So, the required probability is:

[tex]\text{Required probability } = \dfrac{2}{5}\times \dfrac{3}{4} = \dfrac{3}{10} = \bold{30\%}[/tex]

Answer:

30% A

Step-by-step explanation:

[tex]|\Omega|=_{12}C_3=\dfrac{12!}{3!9!}=\dfrac{10\cdot11\cdot12}{2\cdot3}=220\\|A|=4\cdot3\cdot5=60\\\\P(A)=\dfrac{60}{220}=\dfrac{3}{11}\approx0,273[/tex]

Answer:

0.273

Step-by-step explanation:

Total number of balls is 4+3+5 = 12

There are 6 ways to draw 3 different colors (WBR, WRB, BWR, BRW, RWB, RBW) each with a chance of 4/12 · 3/11 · 5/10 = 1/22

So the total chance is 6 · 1/22 = 6/22 = 3/11 ≈ 0.273

Answer:

the other person is right

you should try putting the WHOLE question

Step-by-step explanation:

4) 2x-2y+3 > 0

although it is spelt "26" on the choices

Answer:

x(x + 11)

Step-by-step explanation:

x^2 + 11x when factored gives a result of x(x + 11)

Answer:

x(x+11)

Step-by-step explanation:

We are given the expression:

[tex]x^2+11x[/tex]

This can be factored using the Greatest Common Factor (GCF).

The GCF of x^2 and 11x is x.

Factor out an x.

[tex]x(x+11)[/tex]

x^2+11x factored is: x(x+11).

Answer:

no

Step-by-step explanation:

2(4+10)+20

2(14)+20

28+20

48

Answer:

third option is the first step

Answer:

C

Step-by-step explanation:

It is c bro

Answer:

B. ⅕

Step-by-step explanation:

Fraction of families having more than 2 pets = families with pets of 3 and above ÷ total number of families in the apartment

From the dot plot above, 3 families have 3 pets, and 1 family has 4 pets.

Number of families with more than 2 pets = 3 + 1 = 4

Fraction of families with more than 3 pets = [tex] \frac{4}{20} = \frac{1}{5} [/tex]

The fraction of families that have more than two pets is B. [tex]\frac{1}{5}[/tex]

Given that:

Fraction of families having more than 2 pets = families with pets of 3 and above/total number of families in the apartment

From the dot plot above:

Number of families with more than 2 pets

= 3 + 1

= 4

Fraction of families with more than 3 pets = [tex]\frac{4}{20} = \frac{1}{5}[/tex]

Read more about dot plots here:

https://brainly.com/question/25957672

#SPJ5

Answer:

Median: 14.6, Q1: 6.1, Q3: 27.1, IR: 21, outliers:  none

Step-by-step explanation:

Step 1: order the data from the least to the largest.

2.8, 3.9, 5.3, 6.1, 6.5, 7.1, 12.5, 14.6, 16.4, 16.4, 20.8, 27.1, 28.1, 30.9, 53.5

Step 2: find the median.

The median is the middle value, which is the 8th value in the data set.

2.8, 3.9, 5.3, 6.1, 6.5, 7.1, 12.5, [14.6,] 16.4, 16.4, 20.8, 27.1, 28.1, 30.9, 53.5

Median = 14.6

Step 2: Find Q1,

Q1 is the middle value of the lower part of the data set that is divided by the median to your left.

2.8, 3.9, 5.3, (6.1), 6.5, 7.1, 12.5, [14.6], 16.4, 16.4, 20.8, 27.1, 28.1, 30.9, 53.5

Q1 = 6.1

Step 3: find Q3.

Q3 is the middle value of the upper part of the given data set.

2.8, 3.9, 5.3, 6.1, 6.5, 7.1, 12.5, [14.6], 16.4, 16.4, 20.8, (27.1), 28.1, 30.9, 53.5

Q3 = 27.1

Step 4: find interquartile range (IR)

IR = Q3 - Q1 = [tex] 27.1 - 6.1 = 21 [/tex]

Step 5: check if there is any outlier.

Formula for checking for outlier = [tex] Q1 - 1.5*IR [/tex]

Then compare the result you get with the given values in the data set. Any value in the data set that is less than the result we get is considered an outlier.

Thus,

[tex] Q1 - 1.5*IR [/tex]

[tex]6.1 - 1.5*21 = -25.4[/tex]

There are no value in the given data set that is less than -25.4. Therefore, there is no outlier.

Answer:

correct option is C)  2.8

Step-by-step explanation:

given data

string vibrates form =  8 loops

in water loop formed =  10 loops

solution

we consider  mass of stone = m

string length = l

frequency of tuning = f

volume = v

density of stone = [tex]\rho[/tex]

case (1)  

when 8 loop form with 2 adjacent node is [tex]\frac{\lambda }{2}[/tex]

so here

[tex]l = \frac{8 \lambda _1}{2}[/tex]      ..............1

[tex]l = 4 \lambda_1\\\\\lambda_1 = \frac{l}{4}[/tex]

and we know velocity is express as

velocity = frequency × wavelength   .....................2

[tex]\sqrt{\frac{Tension}{mass\ per\ unit \length }}[/tex]   =   f × [tex]\lambda_1[/tex]

here tension = mg

so

[tex]\sqrt{\frac{mg}{\mu}}[/tex]   =   f × [tex]\lambda_1[/tex]     ..........................3

and

case (2)  

when 8 loop form with 2 adjacent node is [tex]\frac{\lambda }{2}[/tex]

[tex]l = \frac{10 \lambda _1}{2}[/tex]      ..............4

[tex]l = 5 \lambda_1\\\\\lambda_1 = \frac{l}{5}[/tex]

when block is immersed

equilibrium  eq will be

Tenion + force of buoyancy = mg

T + v × [tex]\rho[/tex] × g = mg

and

T = v × [tex]\rho[/tex] - v × [tex]\rho[/tex] × g    

from equation 2

f × [tex]\lambda_2[/tex] = f  × [tex]\frac{1}{5}[/tex]  

[tex]\sqrt{\frac{v\rho _{stone} g - v\rho _{water} g}{\mu}} = f \times \frac{1}{5}[/tex]     .......................5

now we divide eq 5 by the eq 3

[tex]\sqrt{\frac{vg (\rho _{stone} - \rho _{water})}{\mu vg \times \rho _{stone}}} = \frac{fl}{5} \times \frac{4}{fl}[/tex]

solve irt we get

[tex]1 - \frac{\rho _{stone}}{\rho _{water}} = \frac{16}{25}[/tex]

so

relative density [tex]\frac{\rho _{stone}}{\rho _{water}} = \frac{25}{9}[/tex]

relative density = 2.78 ≈ 2.8

so correct option is C)  2.8

Answer:

(DNE,DNE)

Step-by-step explanation:

-24x-12y = -16. Equation one

6x +3y = 4. Equation two

Multiplying equation two with +4 gives

4(6x +3y = 4)

24x +12y = 16...result of equation two

-24x -12y= -16...

A careful observation to the following equation will help us notice that the both equation are same thing.

Multiplying minus to equation one gives

-(-24x-12y=-16)

24x+12y = 16.

Since the both equation are same, there is no solution to it.

Answer:

P [ X < 67 ] =  0,66,81      or    66,81 %

Step-by-step explanation:

We assume Normal Distribution  N ( μ ; σ )    N ( 76 ; 6 )

z score for 67 is :

z(s) =  (  X - μ  ) /σ

z(s) =  (  67 - 76 ) / 6

z(s) =  - 9 / 6

z(s) = - 1,5

with 1,5 we fnd n z-table area undr the curve  α = 0,6681

Then  P [ X < 67 ] =  0,66,81      or    66,81 %

Answer:

[tex]V(m) = (2 + 5m)^3[/tex]

Step-by-step explanation:

Given

Solid Shape = Cube

Edge = 2 feet

Increment = 5 feet per minute

Required

Determine volume as a function of minute

From the question, we have that the edge of the cube increases in a minute by 5 feet

This implies that,the edge will increase by 5m feet in m minutes;

Hence,

[tex]New\ Edge = 2 + 5m[/tex]

Volume of a cube is calculated as thus;

[tex]Volume = Edge^3[/tex]

Substitute 2 + 5m for Edge

[tex]Volume = (2 + 5m)^3[/tex]

Represent Volume as a function of m

[tex]V(m) = (2 + 5m)^3[/tex]

Answer:

217.0588235294118

Step-by-step explanation:

Convert all height to inches.

5' 8" = 68 inches

6' = 72

205/68 = 3.014705882352941

Height/Weight Ratio * Evan's Height = 217.0588235294118

Answer:

(2) If 300 lunches were sold, then 120 chose tacos.

Step-by-step explanation:

We can evaluate each option and see if it makes it true.

For 1: If 200 lunches were served, 10 more students chose pizza over hotdogs.

We can find how many pizzas/hotdogs were given if 200 lunches were served by relating it to 100.

20% chose hotdog, which is [tex]\frac{20}{100}[/tex]. Multiply both the numerator and denominator by two: [tex]\frac{40}{200}[/tex] - so 40 students chose hotdogs.

Same logic for pizza: 30% chose pizza - [tex]\frac{30}{100} = \frac{60}{200}[/tex] so 60.

60 - 40 = 20, not 10, so 1 doesn't work.

2: If 300 lunches were sold, then 120 chose tacos.

Let's set up a proportion again. 40% of 100 is 40.

[tex]\frac{40}{100} = \frac{40\cdot3}{300} = \frac{120}{300}[/tex]

So 120 tacos were chosen - yes this works!

Hope this helped!