Answer:
The value of y is 
Step-by-step explanation:
we know that
A relationship between two variables, x, and y, represent a proportional variation if it can be expressed in the form
or
In a proportional relationship the constant of proportionality k is equal to the slope m of the line and the line passes through the origin
In this problem the line passes through the origin
therefore
Is a proportional variation
Find the value of k
with the point 

The equation is equal to

so
For 
substitute

Answer:
D
Step-by-step explanation:
log₂(x-4) = 4
Undo the log by raising 2 to both sides:
2^(log₂(x-4)) = 2^4
x - 4 = 2^4
x - 4 = 16
x = 20
Answer D.
It's 0.720. you just divide 103 and 143 and get the first three numbers
4 sqrt(400) / 4 sqrt(5)
sqrt(400) =20
4 *20
--------
4 sqrt(5)
the 4's on the top and bottom cancel
20
--------
sqrt(5)
I was taught never to leave a sqrt in the denominator
so you need to multiply by sqrt (5) in the numerator and the denominator
20* sqrt(5)
--------
sqrt(5)* sqrt(5)
20* sqrt(5)
--------
5
= 4 sqrt(5)