When looking at expressions like this,, you need to remember that the square root of a negative number does not exist in the set of Real Numbers. This means that there is no way to simplify this expression,, making the correct answer to your question Undefined.
Let me know if you have any further questions.
:)
So 1 hour= 60 minutes
60+25= 85 minutes
Now we should subtract the 42
85-42=43
Answer:
First image attached
The error was done in Step E, because student did not multiply
by the negative sign in numerator. Step E must be
.
Second image attached
The error was done in Step C, because the student omitted the
of the algebraic identity
. Step C must be 
Step-by-step explanation:
First image attached
The error was done in Step E, because student did not multiply
by the negative sign in numerator. The real numerator in Step E should be:

Hence, Step E must be
.
Second image attached
The error was done in Step C, because the student omitted the
of the algebraic identity
. Step C must be 
And further steps are described below:
Step D

Which according to the Quadratic Formula, represents a polynomial with complex roots. That is: (
,
,
)


(Conjugated complex roots)
Step E

Step F
