I am so sorry this is the wrong answer
Robin’s number ------------ Y
Sydney’s number ------------ x
Y = X + 8.............. (1)
X + Y = 72 ............(2)
Substituting (1) in (2)
X + (X + 8) = 72 .............> ......2X = 64 => X = 32
Now in (1)
Y = (32) + 8 = 40
Robin is 40
Sydney is 32
26) Let f(x)=x4−1x2−1 for x≠−1,1 .
a. Sketch the graph of f .
b. Is it possible to find values k1 and k2 such that f(−1)=k and f(1)=k2 , and that makes f(x) continuous for all real numbers? Briefly explain.
27) Sketch the graph of the function y=f(x) with properties i. through vii.
i. The domain of f is ( −∞,+∞ ).
ii. f has an infinite discontinuity at x=−6 .
iii. f(−6)=3
iv. limx→−3−f(x)=limx→−3+f(x)=2
v. f(−3)=3
vi. f is left continuous but not right continuous at x=3 .
vii. limx→−∞f(x)=−∞ and limx→+∞f(x)=+∞
Answer is:
6162 years
Explanation:
The given equation to use is:
<span>N=Noe^-kt
First, we will need to define the variables of the equation as follows:
No : original amount of C-14 (at t=0)
N : amount of C-14 at certain time (t)
k : a constant equals </span><span>0.0001
t : the time in years
Now, we are given that:
The skeleton contains 54% of it's original amount of C-14. This means that:
N/No = 54% = 0.54
Substitute with this given in the equation given, we will find that the only unknown is the time (t). We can now solve for t as follows:
</span><span>N=Noe^-kt
This can be rewritten as:
N/No = </span>e^-kt
Now,
N/No = e^-kt
0.54 = e^(-0.0001t)
Take ln for both sides:
ln (0.54) = -0.0001t
-0.61618 = -0.0001t
t = 6161.86 years which is approximately 6162 years
Hope this helps :)