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:

Find the length of the field first. To do this, write a formula for the perimeter, P, of the field: P = 210 ft = 2(45 ft) + 2L.
Then 2L = 210 - 90 = 120, and L = 60 (feet).
The area of the field is thus WL = (45 ft)(60 ft) = 2700 sq ft
Answer:
x = 5
Step-by-step explanation:
2 = x-3
<em>Adding 3 to both sides</em>
2+3 = x
5 = x
<u><em>OR </em></u>
x = 5
Answer:
Cos b
Step-by-step explanation:
1/2[sin(a+b)+sin(a-b)]
1/2[sin a cos b +cos a sin b + sin A cos B - cos A sin B]
1/2[2sin a cos b]
sin a cos b