The answer is 5.196152423
Since - x^2=27
X=square root of 27
=5.196152423
Which expression has a value that is equivalent to 5n+13 when n=-15? n^2+13x
Answer:

Step-by-step explanation:
Let the
be the first number,
be the second number and
be the product of the first and second number.
i.e




Now,

Hence, 
7/8 of an hour is 52.5 minutes. 3/10 of 52.5 minutes is 15.75 minutes. They spent 15.75 minutes warming up and cooling down.