Answer:
x = 19
Step-by-step explanation:
A circle has a total of 360 degrees. Because central angles are congruent to the degree measures of their arcs, and because of vertical angles we can construct the equation :
5x+37+5x+37+3x-9-9=360
We can simplify this to :
8x+28=360
Subtract 28, divide 8, and x is 19
I tryed my best to figure out what all of the numbers were. if i got any wrong then please tell me and i will put the right answer in the comments.
1) 3/5= 5/x (cross multiply)
3x=5(5)
3x=25
x= 25/3 -or- 8.33
2) 2/4=x/12<span> (cross multiply</span><span>)
</span> 2(12)=4x
24=4x
6=x
3) 10/x=5/9<span> (cross multiply</span><span>)
10(9)=5x
90=5x
18=x
4) 5/5=x/18</span><span> (cross multiply</span><span>)
5(18)=18x
90=18x
5=x</span>
The formula for exponential decay is

where a is the initial value (28750)
r is the rate of decrease (0.12)
x is the time, in this case in years (6 . 2018-2012 = 6 years)

<span>y </span>≈ <span>13351.62</span>