Since it is given that Boris takes x minutes to run 5 miles it means that Boris' speed will be given as:
.
Now, if Dylan runs slower than Boris and takes 12 more minutes to complete the 5 miles run, then that would mean that Dylan takes (x+12) minutes to complete the same run.
In this case we can see the Dylan's speed will be
.
Thus, the denominator represents the time Dylan takes to run 5 miles if he takes 12 minutes more than Boris.
Therefore, out of the given options, the second option is the correct option.
Answer:

Step-by-step explanation:
The reciprocal of 5: 
The negative reciprocal of 5: 
Answer:x= 5
Step-by-step explanation:
5x-12=63
>5x=63+12=75
>x=75÷5
>x=15
Answer:
it is 27
Step-by-step explanation: