Answer:
The equation of the line L is ![x=2](https://tex.z-dn.net/?f=x%3D2)
Step-by-step explanation:
we know that
The line y=7
Is a horizontal line (parallel line to the x-axis)
The slope of a horizontal line is equal to zero
A line L perpendicular to the given line must be a vertical line (parallel to the y-axis)
The slope of the line L is undefined
The line L passes through the point (2,-5)
therefore
The equation of the line L will be equal to the x-coordinate of the given point
![x=2](https://tex.z-dn.net/?f=x%3D2)
Well, first of all, LCM means Lowest Common Multiple. So you have to write out the factors of each of the numbers. So that will be;
2= 2, 4, 6, 8, 10, 12, 14, 16, 18, 20
5=5, 10, 15, 20
So now, you have to pick out the numbers that are common to both numbers. So;
10, 20
10 and 20 are the only common numbers. So you have to look for the lowest common number. And that is 10. So the LCM is 10.. Hope i helped. Have a nice day.
Answer:
![\sf72 km/h](https://tex.z-dn.net/?f=%5Csf72%20%20km%2Fh)
Step-by-step explanation:
Distance covered by the train in crossing the pole = 100 m.
![\sf Time \: taken=5 \: seconds](https://tex.z-dn.net/?f=%5Csf%20Time%20%5C%3A%20%20taken%3D5%20%5C%3A%20%20seconds)
![\sf \: Speed \: of \: the \: train = \frac{Distance }{Time}](https://tex.z-dn.net/?f=%5Csf%20%5C%3A%20Speed%20%20%5C%3A%20of%20%5C%3A%20the%20%5C%3A%20train%20%3D%20%20%5Cfrac%7BDistance%20%7D%7BTime%7D%20)
![\sf = \frac{100}{5} \: m/s](https://tex.z-dn.net/?f=%5Csf%20%3D%20%20%5Cfrac%7B100%7D%7B5%7D%20%5C%3A%20%20m%2Fs)
![\sf \: = 20 \: m/s](https://tex.z-dn.net/?f=%5Csf%20%5C%3A%20%20%3D%2020%20%5C%3A%20m%2Fs)
![\sf \: = 20 \times \frac{18}{5} \: km/h](https://tex.z-dn.net/?f=%5Csf%20%5C%3A%20%3D%20%2020%20%5Ctimes%20%5Cfrac%7B18%7D%7B5%7D%20%20%5C%3A%20km%2Fh)
![\sf = 72 \: km/h](https://tex.z-dn.net/?f=%5Csf%20%3D%2072%20%5C%3A%20km%2Fh)
- Hence, the speed of the train is 72 km/h
![3x +15= 2x + 10 + x +5\\\\3x-2x-x= 10 +5-15\\\\0=0](https://tex.z-dn.net/?f=3x%20%2B15%3D%202x%20%2B%2010%20%2B%20x%20%2B5%5C%5C%5C%5C3x-2x-x%3D%20%2010%20%20%2B5-15%5C%5C%5C%5C0%3D0)
infinitely many solutions