Answer:

Step-by-step explanation:
Circumference of the column 
Circumference of a circle
Therefore:

Area of a Circle 
Since radius of the cross section of the column =9 meters
Area of the cross section of the column

Answer:
- $85,000 at 6.25%
- $65,000 at 6.00%
Step-by-step explanation:
Let x represent the amount invested at 6.25%. Then the total interest earned is ...
0.0625x + 0.0600(150,000 -x) = 9212.50
0.0025x = 212.50 . . . . . . subtract 9000, collect terms
x = 212.50/0.0025 = 85,000
150,000 - 85,000 = 65,000 . . . . amount invested at the lower rate
$85,000 is invested at 6.25%; $65,000 is invested at 6%.
We have that
<span>t + u = 9 --------> t=9-u-----------> equation 1
9t – 9u = –9----------> equation 2
</span>
I substitute 1 in 2
9*[9-u]-9u=-9
81-9u-9u=-9
18u=81+9
18u=90
u=90/18---------> u=5
t=9-u------> t=9-5----> t=4
the answer is
u=5
t=4
Written in 2-point form, the equation of the line is
y = (y2-y1)/(x2-x1)·(x-x1) +y1
y = (3-(-5))/(-6-(-4))·(x-(-4)) + (-5)
y = 8/-2·(x +4) - 5
y = -4x -21
The value of b is -21.