You can use a tangent:

We have opposite = 17 and adjacent = x.

substitute:
cross multiply
multiply both sides by √3

divide both sides by 3

Use the Pythagorean theorem:

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Other method.
triangle.
The sides are in the ratio 
Therefore

Answer:
2998 ; 17%
Step-by-step explanation:
Given the function:
t(c)=-3970.9(ln c)
c = % of carbon remaining ; t = time
1.) c = 47% = 47/100 = 0.47
t(0.47) = - 3970.9(In 0.47)
t = - 3970.9 * −0.755022
t = 2998.119
t = 2998
B.)
t = 7000
t(c)=-3970.9(ln c)
7000 = - 3970.9(In c)
7000 / - 3970.9 = In c
−1.762824 = In c
c = exp(−1.762824)
c = 0.1715596
c = 0.1715596 * 100%
c = 17.156% ; c = 17%
Answer:
(1, 2)
Step-by-step explanation:
2x-y=0
4x-2=2
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y=2x-0
y=2x
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4x=2+2=4
4x=4
x=4/4=1
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y=2(1)=2
x=1, y=2.