add the rational expressions:

3x/x-1 + 4/7x

i want to completely understand so give a step by step!

usually if it comes to worse, we can always just use the product of all denominators as the LCD, it will just be a CD but not LCD but as good, but usually  we try to use the LCD.

in this case our denominators do not have a GCF, so the LCD will just be their product, so we'll use that.

54 kilometers per hour

step-by-step explanation:

according to rules:

1 km = 1000 meter

which means that 1 meter = 1/1000 km

1 hour = 3600 second [ as 1 hour = 60 min = 60 *60 seconds ]

which means that 1 second = 1/3600 hour

therefore, 1 kilometer/hour =

thus to convert 15 meter per second to kilometer per hour, we multiply 15 to 3.6 kilometer/hour.

15 meter/second=   which is the required answer.