When wiring a house, an electrician knows that the time she will take is given by the formula Time= 2 hours + 12 minutes per lightswitch. She charges her customers a call out fee of £35, plus £20 per hour. How much should a customer be charged for wiring a house with 10 lightswitches?​

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Answer:

  (c)  2440

Step-by-step explanation:

The sum of the squares of numbers 1 .. n is ...

  s(n) = n(n +1)(2n +1)/6

You want the sum of squares from 5 to 19. We can compute that from ...

  s(19) -s(4) = (19(20)(39) -4(5)(9))/6 = (14820 -180)/6 = 2440

Answer:

Step-by-step explanation:

hope it helps u too

Answer:

Because we know that here we have an oscillation, we can model this with a sine or cosine function.

P = A*cos(k*t) + M

where:

k is the frequency

A is the amplitude

M is the midline

We know that at t = 0, we have the lowest population.

We know that the mean is 129, so this is the midline.

We know that the population oscillates 25 above and below this midline,

And we know that for t = 0 we have the lowest population, so:

P = A*cos(k*0) + 129 = 129 - 25

P = A + 129 = 129 - 25

A = -25

So, for now, our equation is

P = -25*cos(k*t) + 129

Because this is a yearly period, we should expect to see the same thing for t = 12 (because there are 12 months in one year).

And remember that the period of a cosine function is 2*pi

Then:

k*12 = 2*pi

k = (2*pi)/12 = pi/6

Finally, the equation is:

P = -25*cos(t*pi/6) + 129

Now we want to find the lowest population was in April instead:

if January is t = 0, then:

February is t = 2

March is t = 3

April is t = 4

Then we would have that the minimum is at t = 4

If we want to still use a cosine equation, we need to use a phase p, such that now our equation is:

P = -25*cos(k*t + p) + 129

Such that:

cos(k*4 + p) = 1

Then:

k*4 + p = 0

p =  -k*4

So our equation now is:

P = -25*cos(k*t  - 4*k) + 129

And for the periodicity, after 12 months, in t = 4 + 12 = 16, we should have the same population.

Then, also remembering that the period of the cosine function is 2*pi:

k*12 - 4*k = 2*pi

k*8 = 2*pi

k = 2*pi/8 = pi/4

And remember that we got:

p = -4*k = -4*(pi/4) = -pi

Then the equation for the population in this case is:

P = -25*cos( t*pi/4 - pi) + 129

Answer:

-65

Step-by-step explanation:

Answer:

7% divided by 1050 is basically 73.5 but the fraction of that is 147/2 hope u find my answer reasonable have a great day.

Step-by-step explanation:

Answer:

B,C,D

Step-by-step explanation:

Square both sides of the equation to get rid of the square root surrounding x.

sqrtX^2 = x and 7^2 = 7*7 = 49

x<49

And since we have a radical, we have to have non-negative solutions (the radical used in the equation actually only means the positive square root) meaning x>0

So which one of the choices is less than 49 and greater than 0?

B,C, and D are all less than 49, and greater than 0

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Answer:

  J. 2085

Step-by-step explanation:

Fill in the desired value for y and solve for x.

  1500 = 50(1.05^x)

  30 = 1.05^x . . . . . . . divide by 50

  log(30) = x·log(1.05) . . . . . take logarithms

  x = log(30)/log(1.05) ≈ 69.71

Since x represents years after December 2015, x = 69.7 will be some time in mid 2085.

Answer:

Step-by-step explanation:

3-digit number is abc. ( just call it)

abc= 9d + 3, meaning abc = 3e

abc = 2k + 1, meaning abc is an odd number

abc = 5t + 4, meaning c = 9 ( because abc is an odd number so c can not be 4)

so a+b must be equal 3.

abc can be 309, 219, 129

5 ÷ 1/2 => 5 x 2/1 => 10/1 => 10

Answer:

10

Step-by-step explanation:

In the pic, it shows ten half squares.  

Answer:

6.667

Step-by-step explanation:

I just did the calculations

Answer:

101 - 37 = 64

I hope this is correct

Answer:

16050, 31.03

Step-by-step explanation:

15000x1.07 (adds 7% tax)=16050

29x1.07(adds 7% tax to price)=31.03

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Answer:

  0, 3, 3, -6, -3

Step-by-step explanation:

Maybe you want to find f(0) in each case. Put 0 where x is, and do the arithmetic.

  f(0) = |0| = 0

  f(0) = |0| +3 = 3

  f(0) = |0 +3| = 3

  f(0) = |0| -6 = -6

  f(0) = |0 +3| -6 = -3

Answer:

8.5

Step-by-step explanation:

Answer:

It will take him 5.85 seconds.

Step-by-step explanation:

12.5 (0.2t - 1) + 21t = 150

Use Distributive Property:

2.5t - 12.5 + 21t = 150

Combine like terms:

23.5t - 12.5 = 150

Subtract 12.5 from both sides:

23.5t = 137.5

Divide both sides by 23.5 to isolate variable t:

5.851063.....

Round to two decimal places (hundredths place):

5.85

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Answer:

Step-by-step explanation:

The volume of a rectangular prism is given by the formula ...

  V = LWH . . . . . the product of length, width, height

This rectangular prism has a volume of ...

  V = (12 ft)(6 ft)(4 ft) = 288 ft³ . . . . rectangular prism volume

__

The volume of a triangular prism is found from the formula ...

  V = Bh

where B is the area of the triangular base, and h is the height of the prism (distance between the triangular bases). The triangular base area is found from ...

  A = 1/2bh . . . . .where b is the base of the triangle, and h is its height.

Here, we have ...

  B = 1/2(6 ft)(4 ft) = 12 ft²

  V = Bh = (12 ft²)(6 ft) = 72 ft³ . . . . triangular prism volume

__

The total volume of the given geometry is the sum of the volumes of the parts:

  aquarium volume = 288 ft³ +72 ft³ = 360 ft³

Answer:

x=12 mile/hour(the speed of the boat)

y=6 mile/hour(the speed of the current)

Step-by-step explanation:

According to the Question,

let, x be the speed of the boat in miles per hour and y be the speed of the current in miles per hour.

x+y=18 ---- Equation 1

x-y=6 ---- Equation 2

On Adding both above Equations We get,

2x=24  ⇔ x=12 mile/hour(the speed of the boat)

& x+y=18 put Value of x=12 we get  ⇔ y=6 mile/hour(the speed of the current)

Given:

Line A goes through (0,y) and (-2,0).

Line B goes through (1,2) and (3,10).

To find:

The value of y for which the system of given linear equation (equation of line A and line B) has no solutions.

Solution:

Two linear equation has no solutions if they are parallel line.

Slope formula:

[tex]m=\dfrac{y_2-y_1}{x_2-x_1}[/tex]

We know that the slopes of two parallel lines are the same.

So, the given system of given linear equation has no solutions if

Slope of line A = Slope of line B

[tex]\dfrac{0-y}{-2-0}=\dfrac{10-2}{3-1}[/tex]

[tex]\dfrac{-y}{-2}=\dfrac{8}{2}[/tex]

[tex]\dfrac{y}{2}=4[/tex]

Multiply both sides by 2.

[tex]\dfrac{y}{2}\times 2=4\times 2[/tex]

[tex]y=8[/tex]

Therefore, the required value of y is 8.

Answer:

x^2+2x-5 - 1/x

Step-by-step explanation:

f(x)=1/x

g(x)=x^2+2x-5

(g-f)(x) = x^2+2x-5 - 1/x

Answer:

c. x² + 2x - 5 - 1 / x

Step-by-step explanation:

f ( x) = 1 / x.

g ( x) = x² + 2x - 5

so,

( g - f) ( x) = x² + 2x - 5 - 1 / x

Answer:

216

Step-by-step explanation:

=>log   36 = -2/3

        m

=>36=(m)^-2/3

=>(root(-36))^3=m

=>m=(root(36))^3

=>m=6^3

=>m=216

2. 22:30

just add 12 on the front

that is the formula

2 If 9:30pm is 21:30,then 10:30pm=22:30 pm

3 15 seconds

4. If 10:30 = 22:30 then 11:50pm = 23:50

16. 3*1.5*1=4.5m^3

I think this are the ones I can try ,I hope this helps.

Answer:

[tex]base = 8 ft\\height =28 ft\\[/tex]

Step-by-step explanation:

let base be x ft. then the height is 3x+4

[tex]Area=\frac{1}{2} \times x \times (3x+4)=112\\3x^{2} +4x=224\\3x^{2} +4x-224=0\\x=8, x=-9.33 (no sol. as length can not be negative)\\ x=8\\base = 8 ft\\height =3(8)+4=28 ft\\[/tex]

Answer:

base = 8 , height = 28

Step-by-step explanation:

Let base be = b

Given:

                             height is 3times base = 3b

        Also 4 feet more than 3 times base = 3b + 4

                           Area = 112 square feet

              [tex]area = \frac{1}{2} \times base \times height\\\\112 = \frac{1}{2} \times b \times (3b+ 4)\\\\224 = b(3b+4)\\\\224 = 3b^2 + 4b\\\\3b^2 + 4b - 224 = 0\\\\[/tex]

The quadratic equation with a = 3 , x = 4 , c = -224

Therefore ,

             [tex]b = \frac{-x \pm \sqrt{x^2 - 4ac}}{2a}\\\\[/tex]

             [tex]b= \frac{-4 \pm \sqrt{4^2 - (4 \times 3 \imes -224)}}{2 \times 3}\\\\b= \frac{-4 \pm \sqrt{16 + 2688}}{6}\\\\b= \frac{-4 \pm \sqrt{2704}}{6}\\\\b= \frac{-4 \pm52 }{6}\\\\b = \frac{-4 + 52}{6} , \ b = \frac{-4 -52}{6}\\\\b = \frac{48}{6} , \ b = -\frac{56}{6}[/tex]

Since base can't be negative base = 8 ft

Therefore , height = 3b + 4 = 3(8) + 4 = 24 + 4 = 28

Answer:

a=1, b=9 and c= 5

Step-by-step explanation:

9/11 divided by 5/11

= 9/11 * 11/5

11 gets cancelled

=9/5

it can also be written as 1* 9/5

Hence here a=1, b=9 and c= 5  

Please mark me as brainliest.

Answer:

I think it's 18.1539073013

i'm  not sure sorry

Answer:

300 computers

Step-by-step explanation:

So I divided 1500 out of a 100 and got 15, then I multiply 15 to 20 and got 300.

(I am a high schooler so I hope this is 3rd grade math because I notice you are a college student and I hope this not some college tricky math, if you get this wrong I am truly sorry)

Answer:

C)  The graph rises to the left and rises to the right.

Step-by-step explanation:

The highest expone tis even and it's coefficient is positive

therefor

The graph rises to the left and rises to the right.

Answer:

look at the domain, where the line is on the x-axis

Step-by-step explanation:

Answer:

[tex]y - 0= \frac{ - 1}{5}( x + 15)[/tex]

Answer:

Step-by-step explanation: