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3 years ago

Score: 0 of 1 pt

Mathematics

1 answer:

Marina CMI [18]3 years ago

5 0

Answer:

Step-by-step explanation:

Let +s+ = the speed of the passenger train

+s+-+20%5D+ = the speed of the freight train

Let +t+ = time in hours for both trains

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

Equation forpassenger train:

(1) +280+=+s%2At+

Equation for freight train:

(2) +180+=+%28+s-20+%29%2At+

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

(1) +t+=+280%2Fs+

Substitute (1) into (2)

(2) +180+=+%28+s-20+%29%2A%28+280%2Fs+%29+

(2) +180s+=+280s+-+5600+

(2) +100s+=+5600+

(2) +s+=+56+

and

+s+-+20+=+36+

The speed of the passenger train is 56 mi/hr

The speed of the freight train is 36 mi/hr

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

check:

(1) +280+=+56%2At+

(1) +t+=+5+

and

(2) +180+=+%28+56-20+%29%2At+

(2) +180+=+36t+

(2) +t+=+5+

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GarryVolchara [31]

Answer:

The answer is option D.

Step-by-step explanation:

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3 years ago

The sum of a number, 1/6 of that number, 2 1/2 of that number, and 7 is 12 1/2. Find the number.

Tema [17]

Answer:

2 $\frac{1}{16}$

Step-by-step explanation:

The question state that; the sum of a number, 1/6 of that number, 2 1/2 of that number, and 7 is 12 1/2. Find the number.

First, we need to interpret and represent this statement mathematically

Let n be the number.

The sum means 'addition'

1/6 of that number is 1/6 of n = 1/6 × n = $\frac{n}{6}$

2 1/2 of that number is 2 1/2 of n = 2 1/2 × n = 5/2 × n = $\frac{5n}{2}$

So the question says that, when we add; $\frac{n}{6}$ , $\frac{5n}{2}$ and 7 all together, the value is 12 1/2

That is;

$\frac{n}{6}$ + $\frac{5n}{2}$ + 7 = 12 1/2

$\frac{n}{6}$ + $\frac{5n}{2}$ + 7 = $\frac{25}{2}$ ( changing 12 1/2 to improper fraction will give $\frac{25}{2}$ )

So we can now go ahead and solve for n

$\frac{n}{6}$ + $\frac{5n}{2}$ + 7 = $\frac{25}{2}$

subtract 7 from both-side of the equation

$\frac{n}{6}$ + $\frac{5n}{2}$ = $\frac{25}{2}$ - 7

$\frac{n + 15n}{6}$ = $\frac{25 -14}{2}$

$\frac{16n}{6}$ = $\frac{11}{2}$

$\frac{16n}{6}$ can be reduced to give us $\frac{8n}{3}$

$\frac{8n}{3}$ = $\frac{11}{2}$

Cross multiply

8n × 2 = 11× 3

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Divide both-side of the equation by 16

$\frac{16n}{16}$ = $\frac{33}{16}$

(On the left-hand side of the equation, 16 will cancel-out 16 leaving us with just, while on the right-hand side of the equation 33 will be divided by 16)

n = $\frac{33}{16}$ = $2\frac{1}{16}$

Therefore the number is $2\frac{1}{16}$

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3 years ago

The slope of a line is undefined, and the x-intercept is -7. what is the equation of the line?

Andreyy89

The equation of line with undefined slope and x - intercept -7 is x = -7

Solution:

Given that the slope of line is undefined and the x intercept is -7

To find: Equation of line

If a line has undefined slope, then it is a vertical line

A vertical line has undefined slope because all points on the line have the same x-coordinate

The equation of a vertical line always takes the form:

x = b

where, "b" is the x - intercept

Given x - intercept is -7

Thus the equation of line is:

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3 years ago

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stepan [7]

Answer:

Step-by-step explanation:

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That's a right angle triangle also.

measure of ∠E to the nearest degree

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sin∠E = 0.8873

∠E= sin^-1 0.8873

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ZanzabumX [31]

Answer:

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