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:
Step-by-step explanation:
-7z/2 - 2 + z -3
=-5 - 5z/2
Answer:
x = -7
Step-by-step explanation:
5x+8=3x-6
Subtract 3x from each side
5x-3x+8=3x-3x-6
2x+8 = -6
Subtract 8 from each side
2x+8-8 = -6-8
2x = -14
Divide by 2
2x/2 = -14/2
x = -7
60 blocks in 30 min
18 blocks in 9 min
Method 1
60-18 = 42
42 blocks in 21 min
Method 2
30-9 =21 min