Answer:
y =
x + ![\frac{44}{5}](https://tex.z-dn.net/?f=%5Cfrac%7B44%7D%7B5%7D)
Step-by-step explanation:
the equation of a line in slope- intercept form is
y = mx + c ( m is the slope and c the y-intercept )
rearrange 12x - 5y = - 44 into this form
subtract 12x from both sides
- 5y = - 12x - 44 ( divide all terms by - 5 )
y =
x +
← in slope- intercept form
Well 2.26 as a fraction is
![2 \times \frac{13}{50}](https://tex.z-dn.net/?f=2%20%5Ctimes%20%5Cfrac%7B13%7D%7B50%7D%20)
^Whole Fraction^
but as an Improper Fraction I is
Could you please give me more of a description?
Answer:
The correct answer is:
Between 600 and 700 years (B)
Step-by-step explanation:
At a constant decay rate, the half-life of a radioactive substance is the time taken for the substance to decay to half of its original mass. The formula for radioactive exponential decay is given by:
![A(t) = A_0 e^{(kt)}\\where:\\A(t) = Amount\ left\ at\ time\ (t) = 75\ grams\\A_0 = initial\ amount = 1000\ grams\\k = decay\ constant\\t = time\ of\ decay = 2500\ years](https://tex.z-dn.net/?f=A%28t%29%20%3D%20A_0%20e%5E%7B%28kt%29%7D%5C%5Cwhere%3A%5C%5CA%28t%29%20%3D%20Amount%5C%20left%5C%20at%5C%20time%5C%20%28t%29%20%3D%2075%5C%20grams%5C%5CA_0%20%3D%20initial%5C%20amount%20%3D%201000%5C%20grams%5C%5Ck%20%3D%20decay%5C%20constant%5C%5Ct%20%3D%20time%5C%20of%5C%20decay%20%3D%202500%5C%20years)
First, let us calculate the decay constant (k)
![75 = 1000 e^{(k2500)}\\dividing\ both\ sides\ by\ 1000\\0.075 = e^{(2500k)}\\taking\ natural\ logarithm\ of\ both\ sides\\In 0.075 = In (e^{2500k})\\In 0.075 = 2500k\\k = \frac{In0.075}{2500}\\ k = \frac{-2.5903}{2500} \\k = - 0.001036](https://tex.z-dn.net/?f=75%20%3D%201000%20e%5E%7B%28k2500%29%7D%5C%5Cdividing%5C%20both%5C%20sides%5C%20by%5C%201000%5C%5C0.075%20%3D%20e%5E%7B%282500k%29%7D%5C%5Ctaking%5C%20natural%5C%20logarithm%5C%20of%5C%20both%5C%20sides%5C%5CIn%200.075%20%3D%20In%20%28e%5E%7B2500k%7D%29%5C%5CIn%200.075%20%3D%202500k%5C%5Ck%20%3D%20%5Cfrac%7BIn0.075%7D%7B2500%7D%5C%5C%20k%20%3D%20%5Cfrac%7B-2.5903%7D%7B2500%7D%20%5C%5Ck%20%3D%20-%200.001036)
Next, let us calculate the half-life as follows:
![\frac{1}{2} A_0 = A_0 e^{(-0.001036t)}\\Dividing\ both\ sides\ by\ A_0\\ \frac{1}{2} = e^{-0.001036t}\\taking\ natural\ logarithm\ of\ both\ sides\\In(0.5) = In (e^{-0.001036t})\\-0.6931 = -0.001036t\\t = \frac{-0.6931}{-0.001036} \\t = 669.02 years\\\therefore t\frac{1}{2} \approx 669\ years](https://tex.z-dn.net/?f=%5Cfrac%7B1%7D%7B2%7D%20A_0%20%3D%20A_0%20e%5E%7B%28-0.001036t%29%7D%5C%5CDividing%5C%20both%5C%20sides%5C%20by%5C%20A_0%5C%5C%20%5Cfrac%7B1%7D%7B2%7D%20%3D%20e%5E%7B-0.001036t%7D%5C%5Ctaking%5C%20natural%5C%20logarithm%5C%20of%5C%20both%5C%20sides%5C%5CIn%280.5%29%20%3D%20In%20%28e%5E%7B-0.001036t%7D%29%5C%5C-0.6931%20%3D%20-0.001036t%5C%5Ct%20%3D%20%5Cfrac%7B-0.6931%7D%7B-0.001036%7D%20%5C%5Ct%20%3D%20669.02%20years%5C%5C%5Ctherefore%20t%5Cfrac%7B1%7D%7B2%7D%20%20%5Capprox%20669%5C%20years)
Therefore the half-life is between 600 and 700 years