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Here's (a) and (c)

(a)   (-4, 4)   and  (4, -4)  are on f(x)

So....  (-2, 4)  and (2, -4)   are on f(2x)  ....so     a=  -2  and b = 2

(c)  To find c we need to solve  this

2c -  8  = -4     add 8 to both sides

2c  = 4

c  = 2

To find d we need to solve this

2c - 8  = 4  add 8 to both sides

2c = 12

c  = 6

Good thing you got that "Fool" across the bridge, GA.......these guys get a liitle perturbed at late arrivals....!!!!!

2y+7=3y-4

2y-3y=-4-7

-1y=-11

-1y/-1=-11/-1

y=11

13.3

d / 26  =  g

Welcome, Jamesm88!

One way to think about this type of questions is to make sure that the units on both sides are equal. 

Consider the left hand side of the equation which is always velocity squared. Since [v] = m^1 * s^(-1) we know that the unit for v^2 is m^2 * s(-2)

Consider the right hand side, all of them have a force T which has the unit kg^1 * m^1 * s^(-2)

Now let's look closer at the available options. In order for the right hand side be equal to the left hand side we need to get rid of one unit of kg and get one more unit of m.

If you look at the options m happens to be the mass and  x the length. Therefore we can see that dividing by one m we can balance the kg part and by multiplying one x we will get an additional m(meters) in the equation. Therefore the answer C has to be correct, we can double check this by putting in the units of all values to check:

\(\frac{\text{m}^2}{\text{s}^2}= \frac{\text{kg}^1 \space \text{m}^1}{\text{s}^2} \cdot \text{kg}^{-1} \cdot \text{m}^1\)

We can see that it works out and gives us the correct units!

Dude its the easiest question i have ever solved

Well, then. Hello!

The sum of the two angles is  180°  because together they form a straight line.

(9x + 9)°  +  (6x + 6)°  =  180°

9x + 9  +  6x + 6  =  180                  Combine like terms on the left .

15x + 15  =  180              Subtract  15  from both sides.

15x  =  165                      Divide both sides by  15 .

x  =  11

The larger angle measures     (9x + 9)°   =   (9(11) + 9)°   =   (99 + 9)°   =   108°

The smaller angle measures     (6x + 6)°   =   (6(11) + 6)°   =   (66 + 6)°   =   72°

Let's call one of the angles  " a "  and the other angle  " b " .

Let     a  =  52° + 3b

and since the angles are supplementary,

a + b  =  180°          In this equation, substitute  52° + 3b  in for  a .

52° + 3b + b  =  180°              Subtract  52°  from both sides of the equation.

3b + b  =  180° - 52°               Combine like terms.

4b  =  128°                             Divide both sides by  4 .

b  =  32°

And since   a + b  =  180°  ,   a   =   180° - b   =   180° - 32°   =   148°

a  =  148°

Thanks Ginger, 

Can you try and explain your 30+F  and 30-F a bit please.

(F=fools speed )

I think you have said that the time taken if the man runs towards the train is   \(\frac{1b}{30-F} \qquad \text{where 4b is the length of the bridge}\\\)

this is distance /effective speed.

And the time taken if the man runs away from the train is  \(\frac{3b}{30+F}\)

BUT i don't really understand the concept of the relative speeds :/

Thanks Ginger, I like your logic

I have done this but I have effectively said that the train has no length and the man has no width and they both arrive at the end of the bridge at the same time. So effectively the speed would have to be greater.  

Since he can only just get to either end in time then the train must be coming in the opposite direction to the man.

Let the length of the bridge be 4b, so the man has crossed a distance of 3b and has 1b left to traverse.

Let the man be jogging v km/h

Let the distance that the train is from the bridge be k km

The train is traveling at 30km/h

\(\boxed{speed=\frac{distance}{time}\\ time=\frac{distance}{speed}}\)

If the man continues forward then it will take him b/v to get to the end of the bridge.

In this time the train will travel for x/30 hours

so

\(\frac{b}{v}=\frac{x}{30}\\ x=\frac{30b}{v}\)

If the man runs in the opposite direction  then it will take him 3b/v hours to get to the end of the bridge.

In this time the train will travel for (x+4b)/30 hours

so

\(\frac{3b}{v}=\frac{x+4b}{30}\\ \frac{90b}{v}=x+4b\\ \frac{90b}{v}-4b=x\\\)

so

\(\frac{90b}{v}-4b=\frac{30b}{v}\\ \frac{90}{v}-4=\frac{30}{v}\\ 90-4v=30\\ 60=4v\\ v=15km/hour \)

The speed has to be minimally greater than 15km/hour

So I think A is the answer sought

I can see that i made my answer a little more complicated than necessary 

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Although this subtly phrased question appears to lack sufficient information for a solution. It does in fact have one. 

Part of the information is contained in this phrase.

if it is possible for the jogger to just escape being hit by the train by running at full speed to either end of the bridge

Here the use of the word “if” is not so much a conditional clause, as it is a presented condition or supposition.  Rephrasing makes this more clear:

"Suppose the jogger can just barely escape being hit by the train by running to either end of the bridge at his greatest speed."

This tells us the runner will meet the train at end of the bridge and just miss being hit, whether he runs toward the train or away from the train. Along with this information, there are two pieces of numerical data: the train’s 30kph speed and the man’s relative position of 3/4 on the bridge. 

Using this information, set up an equation where the train and the man meet at either end of the bridge.   

\(\dfrac{(30 + F) }{(30-F)} = \dfrac{3}{1} \tiny \text { F is the speed the Fool can run.}\\ (30+F) =3(30-F)\\ 30+F = 90-3F\\ 4F = 60\\ \,\;F= \dfrac{60}{4}\\ \,\\ F = 15kph\\ \)

Answer  (A). 

I don't think f(x)=3-x  is a reciprocal function. 
I'm pretty sure it is a linear function.

ok this might get moderated but

Have you ever watched a video that was so funny that you actually spit out milk?

But you wern't drinking any milk?

( ͡° ͜ʖ ͡°)

2x+50  +  x+25 = 180       adjacent supplementary angles

              3x+75 =180

                x+25  = 60

                    x  =    35

2x+50 = 70+50 = 120

5x-55 =  175 - 55 = 120

These two angles ae corresponding angles and since they are congruent (equal) they must be on parallel lines.

Therefore  AC is parallel to DF

I think......Because it is possible for him to survive by running to either end, then he must be heading toward the train.  If he runs backward, he has the advantage running in the same direction as the train, but he has to run  3/4  of the bridge.  If he runs forward, he has the advantage of only having to run  1/4  of the bridge, but he and the train are heading toward each other.

I think your question is missing a number of important points:

You say " he sees a train coming", but don't specify whether it is coming behind him or towards him.

Also, since he completed 3/4 of his run(presumably 3/4 of the length of the bridge", you say:

"and if it is possible for the jogger to just escape being hit by the train by running at full speed to either end of the bridge, what is the minimum speed, in km/h" !!

Why would he run to "either end of the bridge", since he had already completed 3/4 of the span of the bridge. Surely, he would finish running the remaining 1/4 of the bridge, to get out of harm's way, since it would take him a lot LESS time to get off the bridge.

Volume of triangular Pyramid = V = 1/3AH, where A=Area of the base, H=Height. So,

300 =1/3A*3

300 =1/3*3*A

300 =A, or

Area of the base =300 m^2.

Solve the following system:
{x + y = 74 | (equation 1)
2 x + 4 y = 196 | (equation 2)

Swap equation 1 with equation 2:
{2 x + 4 y = 196 | (equation 1)
x + y = 74 | (equation 2)

Subtract 1/2 × (equation 1) from equation 2:
{2 x + 4 y = 196 | (equation 1)
0 x - y = -24 | (equation 2)

Divide equation 1 by 2:
{x + 2 y = 98 | (equation 1)
0 x - y = -24 | (equation 2)

Multiply equation 2 by -1:
{x + 2 y = 98 | (equation 1)
0 x+y = 24 | (equation 2)

Subtract 2 × (equation 2) from equation 1:
{x+0 y = 50 | (equation 1)
0 x+y = 24 | (equation 2)

x = 50 Humans     and          y=24 Horses