15
Explanation:
If y varies inversely as x, the two variables can be represented in an equation in the form
y
=
k
x
where
k
is some constant.
We are given that
y
=
5
when
x
=
6
. We can plug this into the above equation to find what
k
is:
5
=
k
6
30
=
k
Based on this we can create our equation:
y
=
30
x
And then find
x
when
y
=
2
:
2
=
30
x
2
x
=
30
x
=
15
The answer would be -0.012345679.
The first thing you would do is substitute 3 in for x, seeing that you've told us x = 3. After you've substituted x, the equation would look something like:
f(3) = -3^-4. From here, all you have to do is solve! -3 to the power of -4 equals -0.012345679. Therefor, f(3) = -3^-4 equals -0.012345679
It is 4 because the diameter is twice longer than the radius!
I. ) f ( 3 ) = 36 + 2 = 8
II. ) f ( x ) = ( 3 x - 4 ) / 5
y = ( 3 x - 4 ) / 5
5 y = 3 x - 4
5 y + 4 = 3 x
x = ( 5 y + 4 ) / 3
f-1(x ) = ( 5 x + 4 ) /3
f-1(4) = ( 20 + 4 ) / 3 = 24/3 = 8
III. ) y + 10 = 2 y + 1
- y = - 9
y = 9
Answer: The same result have I. and II.