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FromTheMoon [43]
2 years ago
9

A loaded moving truck is traveling 30 mph faster than a freight train. in the time it takes the train to travel 135 miles, the t

ruck travels 225 miles. find the speed of the truck
Mathematics
1 answer:
Alina [70]2 years ago
4 0
Speed of truck= x
speed of train=x-30
A loaded moving truck is traveling 30 mph faster than a freight train. in the time it takes the train to travel 135 miles, the truck travels 225 miles. find the speed of the truck.

A loaded moving truck is traveling 30 mph faster than a freight train...
(x-30)=speed of train
the time it takes the train to travel 135 miles, the truck travels 225 miles...
135/(x-30)=225/x
the you multiply on both sides the x values and get...
 135x=225x-6750
then you subtract 225x on both sides...
-90x=-6750
then you divide -90 on both sides...
x=75
the speed of the truck is 75mph
i hope this helped give me a thanks and a 5 star rating if it helped! c:



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Pavel [41]

The area of the ellipse E is given by

\displaystyle\iint_E\mathrm dA=\iint_E\mathrm dx\,\mathrm dy

To use Green's theorem, which says

\displaystyle\int_{\partial E}L\,\mathrm dx+M\,\mathrm dy=\iint_E\left(\frac{\partial M}{\partial x}-\frac{\partial L}{\partial y}\right)\,\mathrm dx\,\mathrm dy

(\partial E denotes the boundary of E), we want to find M(x,y) and L(x,y) such that

\dfrac{\partial M}{\partial x}-\dfrac{\partial L}{\partial y}=1

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\begin{cases}M(x,y)=\dfrac x2\\\\L(x,y)=-\dfrac y2\end{cases}\implies\begin{cases}\dfrac{\partial M}{\partial x}=\dfrac12\\\\\dfrac{\partial L}{\partial y}=-\dfrac12\end{cases}\implies\dfrac{\partial M}{\partial x}-\dfrac{\partial L}{\partial y}=1

The line integral is then

\displaystyle\frac12\int_{\partial E}-y\,\mathrm dx+x\,\mathrm dy

We parameterize the boundary by

\begin{cases}x(t)=5\cos t\\y(t)=17\sin t\end{cases}

with 0\le t\le2\pi. Then the integral is

\displaystyle\frac12\int_0^{2\pi}(-17\sin t(-5\sin t)+5\cos t(17\cos t))\,\mathrm dt

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###

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\begin{cases}x(t)=4\cos^3t\\y(t)=4\sin^3t\end{cases}

which gives

x(t)^{2/3}+y(t)^{2/3}=(4\cos^3t)^{2/3}+(4\sin^3t)^{2/3}=4^{2/3}(\cos^2t+\sin^2t)=4^{2/3}

as needed. Then with 0\le t\le2\pi, we compute the area via Green's theorem using the same setup as before:

\displaystyle\iint_E\mathrm dx\,\mathrm dy=\frac12\int_0^{2\pi}(-4\sin^3t(12\cos^2t(-\sin t))+4\cos^3t(12\sin^2t\cos t))\,\mathrm dt

=\displaystyle24\int_0^{2\pi}(\sin^4t\cos^2t+\cos^4t\sin^2t)\,\mathrm dt

=\displaystyle24\int_0^{2\pi}\sin^2t\cos^2t\,\mathrm dt

=\displaystyle6\int_0^{2\pi}(1-\cos2t)(1+\cos2t)\,\mathrm dt

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So, in your case, you're wondering what percentage of 28 does 9 represent. So, the formula becomes

\dfrac{9}{28}\times 100 = 0.32\overline{142857}\times 100 = 32.\overline{142857} \approx 32.14\%

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Your friend is trying to grow her hair as long as her cousin’s hair. The table shows their hair lengths y (in inches) in differe
Effectus [21]
<span>Given the table that shows the hair lengths y (in inches) of your friend and her cousin in different months x.

Month      Friends Hair(in)      Cousins Hair(in)
    3                     4                              7
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To solve for the cousins hair, recall that the equation of a line is given by

y = mx + c

From the table,

7 = 3m + c . . . (1)
9 = 8m + c . . . (2)

(1) - (2) ⇒ -2 = -5m
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Substituting for m into equation (1) gives:

7=3(0.4)+c \\  \\ \Rightarrow c=7-1.2=5.8

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1 year ago
Let f(x)=−3x. The graph of f(x) ​is transformed into the graph of g(x) by a vertical stretch of 4 units and a translation of 4 u
deff fn [24]
<h2>Answer:</h2>

Ques 1)

                   g(x)=-12x+48

Ques 2)

                 g(x)=|3x|+4

<h2>Step-by-step explanation:</h2>

Ques 1)

We know that if a graph is stretched by a factor of a then the transformation if given by:

    f(x) → a f(x)

Also, we know that the translation of a function k units to the right or to the left is given by:

  f(x) →  f(x+k)

where if k>0 then the shift is k units to the left

and if k<0 then the shift is k units to the right.

Here the graph of f(x) ​is transformed into the graph of g(x) by a vertical stretch of 4 units and a translation of 4 units right.

This means that the function g(x) is given by:

g(x)=4f(x-4)\\\\i.e.\\\\g(x)=4(-3(x-4))\\\\i.e.\\\\g(x)=-12(x-4)\\\\i.e.\\\\g(x)=-12x+48

Ques 2)

We know that the transformation of the type:

  f(x) → f(x)+k

is a shift or translation of the function k units up or down depending on k.

If k>0 then the shift is k units up.

and if k<0 then the shift is k units down.

Here, The graph of the function f(x)=|3x| is translated 4 units up.

This means that the transformed function g(x) is given by:

                 g(x)=|3x|+4

4 0
1 year ago
Suppose again that we are counting the ways to distribute exams to TAs and it matters which students' exams go to which TAs. The
abruzzese [7]

The question is incorrect.

The correct question is:

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There are a total of 60 exams to grade.

(c) Suppose again that we are counting the ways to distribute exams to TAs and it matters which students' exams go to which TAs. The TAs grade at different rates, so the first TA will grade 25 exams, the second TA will grade 20 exams and the third TA will grade 15 exams. How many ways are there to distribute the exams?

Answer: 60!/(25!20!15!)

Step-by-step explanation:

The number of ways of arranging n unlike objects in a line is n! that is ‘n factorial’

n! = n × (n – 1) × (n – 2) ×…× 3 × 2 × 1

The number of ways of arranging n objects where p of one type are alike, q of a second type are alike, r of a third type are alike is given as:

n!/p! q! r!

Therefore,

The answer is 60!/25!20!15!

6 0
1 year ago
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