Find the zeros using the quadratic formula x^2-5x+4=y.

It takes a train 60 seconds to completely drive through a bridge of 1260 m, and 90 seconds to completely drive through a tunnel

Olegator [25]

The length of train is 120 meters

The speed of train is 25 meter per second

Solution:

The speed is given by formula:

$speed = \frac{distance}{time}$

Given that,

It takes a train 60 seconds to completely drive through a bridge of 1260 m

And 90 seconds to completely drive through a tunnel of 2010 m

Let the length of the train be "x"

The total distance travelled by the train across the bridge is given by:

total distance = x + 1260 + x = 2x + 1260

[ here we use x + x to represent that train completely drives through bridge ]

The time taken is given as 60 seconds

Therefore, the speed is given as:

$speed = \frac{2x+ 1260}{60}$

The total distance travelled by the train through the tunnel is given by:

total distance = x + 2010 + x = 2x + 2010

The time taken is given as 90 seconds

Therefore, the speed is given as:

$speed = \frac{2x+ 2010}{90}$

The speed of the train was the same in both cases.

Equate both speeds

$\frac{2x+ 1260}{60} = \frac{2x+ 2010}{90}$

$\frac{x+630}{30} = \frac{x+1005}{45}$

$45(x+630) = 30(x+1005)\\\\45x + 28350 = 30x + 30150\\\\45x - 30x = 30150 - 28350\\\\15x = 1800\\\\x = 120$

Thus length of train is 120 meters

Find the speed of train:

$speed = \frac{2x+ 1260}{60}\\\\speed = \frac{2(120) + 1260)}{60}\\\\speed = 25$

Thus speed of train is 25 meter per second

5 0

3 years ago

Need some help, please. What do I plot? I attempted to figure the questions out many times, but I've come to no clear conclusion

olganol [36]

Answer:

vertex is (4,-4) and another point is (6,0) or you could use (2,0) or many other options :)

Step-by-step explanation:

The cool thing about this question your quadratic is in factored form so your x-intercepts are easy to figure out, they are 2 and 6.

So you can plot (6,0) and (2,0).

The vertex will lie half between x=2 and x=6... so it lays at (6+2)/2=4

We just have to find the y-coordinate for when x=4.

Plug in 4 gives you (4-2)(4-6)=(2)(-2)=-4.

So the vertex is at (4,-4).

5 0

4 years ago

Fill in the blank to complete the calculation using the distributive property.

Minchanka [31]

Where’s the picture of the question or the blank?

4 0

3 years ago

Value of 2x when x = 5

lora16 [44]

Answer: 10

Step-by-step explanation:

My answer is correct because, if x=5 then were just multiplying 2 times 5 since 5 is not on the top like $2^{5}$ because if it was that means we have to multiply 2 by itself 5 times. But since its not a exponent you just multiply 2 times 5. And 2 x 5= 10.

Hope This Helps!

8 0

3 years ago

Read 2 more answers

How many square inches in a foot

Cloud [144]

Answer:

There are 144 square inches in a square foot.

Step-by-step explanation:

A square foot is a square that is 1 foot by 1 foot. Since there are 12 inches in 1 foot, and to get the area you need to multiple 2 adjacent sides together, you do 12 times 12 which is 144 square inches. Many people have the misconception that a square foot has 12 square inches, but this is wrong since a square foot has dimensions of 12 inches by 12 inches, but when you multiply them together, you can see that the answer is actually 144.

5 0

3 years ago