Answer:
a) 1/27
b) 16
c) 1/8
Step-by-step explanation:
a) 
One of the properties of the exponents tells us that when we have a negative exponent we can express it in terms of its positive exponent by turning it into the denominator (and changing its sign), so we would have:

And now, solving for x = 9 we have:

b) 
This is already a positive rational exponent so we are just going to substitute the value of y = 8 into the expression

c) 
Using the same property we used in a) we have:

And now, solving for z = 16 we have:

Answer:2 and 5
Step-by-step explanation:
Answer:
The graph in the attached figure
Step-by-step explanation:
we have
-----> equation A
-----> equation B
we know that
The solution of the system of equations is the intersection point both graphs
In this problem
The intersection point is 
therefore
The solution is the point 
using a graphing tool
see the attached figure
Answer: -57
Step-by-step explanation:
15 + ( - 72)
Distribute
15 - 72
When this happens, you subtract the smaller number by the bigger one, then put the sign that was on the bigger number on what you get.
72 - 15 = 57
Put a negative sign on 57
-57
15 + (-72) = -57
Answer: 9
Step-by-step explanation:
We will use the Order of Operations to solve.
Given:
4 – 15 ÷ (30 – 33)
Subtract 33 from 30:
4 – 15 ÷ (– 3)
Divide -15 by -3:
4 + 5
Add 4 to 5:
9