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:
The measure of the angles in degree is 57.5 degrees
Step-by-step explanation:
If two angles are congruent, they are equal in value
Let the number be x
2x + 3 = 3x-54.5
Thus;
3x-2x = 54.5 + 3
x = 57.5
Answer:
33.33 percent are not riding the bus
Step-by-step explanation:
Given:
must correctly answer 80% of the questions
correctly answered questions = 26
incorrectly answered questions = 4
unanswered questions = 15
Total questions = 26 + 4 + 15 = 45
45 * 80% = 36 required correctly answered questions.
36 - 26 = 10
Out of 15 remaining questions, 10 questions must be correctly answered for Heidi to advance to the next level.