For this case we must solve the following questions:
Question 1:
We should simplify the following expression:

Applying double C we have:

By definition of multiplication of powers of the same base we have to place the same base and add the exponents:
Canceling common terms:

Answer:
Option A
Question 2:
We should simplify the following expression:

So, we have:

Simplifying common terms:

Answer:
Option D
Question 3:
We factor the following expressions to rewrite the experience:
<em>
: </em>We look for two numbers that multiplied give 10 and added 7:

<em>
</em> We look for two numbers that multiplied give -50 and added -5:

<em>
</em>
Rewriting the given expression we have:

We simplify common terms in the numerator and denominator we have:

Answer:
Option D