Here's the answer for your problem
log₉(<em>x</em> - 7) + log₉(<em>x</em> - 7) = 1
2 log₉(<em>x</em> - 7) = 1
log₉(<em>x</em> - 7) = 1/2
Take the base-9 antilogarithm of both sides; in other words, make both sides powers of 9:
can also be written as √9 = 3, and 
, so the equation reduces to
<em>x</em> - 7 = 3
Solve for <em>x</em> :
<em>x</em> = 10
Let us assume the amount of money invested in CD = x
Then
Amount of money invested in savings bond = 6000 - x
Percentage of interest in CD = 4%
Percentage of interest in savings bond = 7%
Amount of interest gained in 1 year = $360
Now
0.04x + [(6000 - x) * 0.07] = 360
0.04x + 420 - 0.07x = 360
0.03x = 60
x = 2000
Then
Amount of money invested in the CD account = $2000
Amount of money invested in savings bond = 6000 - 2000
= 4000 dollars
Volume of the sphere = 3/4 pi r^3
The spheres radius is one third of the hemisphere's so radius of hemisphere = 3r
Volume of the hemisphere = 1/2 * 4/3 pi (3r)^3
= 2/3 * 27 pi r^3
= 18 pi r^3
So vol hemisphere / vol sphere = 18 pi r^3 / 4/3 pi r^3 = 18 * 3/4 = 13.5
Hemisphere is 13.5 times the volume of the sphere.
It's a bit tedious, but it's just a bunch of factoring and manipulation.
