Answer:
Length = 7 Width = 2
Step-by-step explanation:
L = Length
W = Width
L=9w-11
2L+2W=18
2(9W-11) + 2W = 18
18W - 22 +2W = 18
20W -22 = 18
20W = 40
W = 2
L = 9(2)-11
L=18-11
L=7
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Answer:
a)
, b)
, c)
, d) 
Step-by-step explanation:
a) Let assume an initial mass m decaying at a constant rate k throughout time, the differential equation is:

b) The general solution is found after separating variables and integrating each sides:

Where
is the time constant and 
c) The time constant is:


The particular solution of the differential equation is:

d) The amount of radium after 300 years is:

they amount of money are not the same
reason why;
the reason why its not the same is because 2x8x9=144 and 3x9x12=324 and the amount of money spent is different
Answer:
n = 13
Step-by-step explanation:
The sum of the measures of the interior angles of an n-sided polygon is
(n - 2)180
Set (n - 2)180 equal to 1980 and solve for n.
(n - 2)180 = 1980
Divide both sides by 180.
n - 2 = 11
Add 2 to both sides.
n = 13