Answer:
Step-by-step explanation:
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:
To solve using completing square, we need to write the equation as x2+3x=17.
The next step is to add a number such that the square can be completed. The number must be equal to (b/2a)^2, so here it will be (3/2)^2 = 9/4
The equation then becomes x2+3x+(9/4)=17+(9/4).
Solving it further will get you the final answer
Let t represent Todd's age now.
.. 4(t -3) -(t -3) = 81 . . . . . . 3 years ago, their differnce in ages was 81.
.. 3t -9 = 81
.. t = (81 +9)/3 = 30
Todd is 30 now.
_____
You can also work this by considering "ratio units." 3 years ago, the ratio of their ages was 4:1, a difference of 3. That difference corresponds to 81 years, so each "ratio unit" represents 81/3 = 27 years. Todd's age then was 1 ratio unit, 27 years. Now, Todd's age is 30.
width= 7m
Step-by-step explanation:
Area= L×W
L= (x+8)m
W=8m
105m²= (x+8)m × (x)m
105m²= x² + 8x
-x² - 8x + 105= 0
(x-7) (x+15) = 0
x= 7 x= -15
x=width = 7m