To solve this question we will use two important formulas.
The first formula involves the calculation of the decay constant, 
which is to be found as:
where 
is the half life of Pb-210 which is given to be 22 years in the question.
Thus, 
Now, we will use the second formula which is called the function of decay formula and is given as:
where 
percentage of Pb-210 remaining in the bone at present, which in our case is 67% or 0.67
percentage of Pb-210 to start with, which is always 100% or 1.
Plugging in all these values in the decay formula we are supposed to find the time, 
.
Taking natural log on both sides we get:
years
Therefore the bone fragment is about 12.71 years old.
Step-by-step explanation:
first you do x/5=10-6 the second step you do is x/5=4 the third step is x=4x5 finally the answer is x=20
The answer for the ones you've marked.
1. y= 1 | x= -2
6. X= -7 | y= -6
the idea is simple here an example on how to solve them:
Answer:
x = 1
Step-by-step explanation:
We know that the two angles must be equal to each other. So:
65x - 12 = 43x + 10
First add 12 to both sides:
65x - 12 + 12 = 43x + 10 + 12
65x = 43x + 22
Then subtract 43x from both sides:
65x - 43x = 43x - 43x + 22
22x = 22
x = 1
<span>Area of the upper rectangle = x(16 - 6) = 10x </span>yd²<span>
Area of the bottom rectangle = 6(x + 6) = 6x + 36 </span>yd²<span>
Total area = 10x + 6x + 36 = 16x + 36 yd</span>²
