Answer:

Step-by-step explanation:
The domain of a rational function is all real numbers <em>except </em>for when the denominator equals 0.
So, to find the domain restrictions, set the denominator to 0 and solve for x.
We have the rational function:

Set the denominator to 0:

Subtract 9:

So, the domain is all real numbers except for -9.
In other words, our domain is all values to the left of negative 9 and to the right of negative 9.
In interval notation, this is:

And we're done :)
Answer:
thank u
Step-by-step explanation:
Let the distance be x miles
Time = Distance / speed
Time taken by Mike to go to his friend's house = x / 40 hours
Time taken by him to return = x / 45 hours
Total time = x / 40 + x / 45 = 4 hours
= 9x + 8x = 1440 miles
17x = 1440
= x = 1440 ÷ 7
= x = 84.706
Time taken to return home = 84.706 /45= 1.882 hours .
Therefore , Mike took 1.882 hours to reach home .