The half-life of the radioactive substance can be determined through teh equation ln 2 = k (t 1/2) where k is equal to ln (1/(1-0.58)) / 3. Hence t 1/2 is equal to 2.40 days. To decay to 10% of the original amount, ln (1/0.90) / ( ln2) / 2.40, time is equal to 0.37 days.
Answer:
67
Step-by-step explanation:
Since the diagonals in a rectangle are congruent, AC=BD and
7x+18=10x-3
We need to separate x -- to do that, we can first subtract 7x from both sides, resulting in
18=3x-3
Next, add 3 to both sides to get
21=3x
Divide both sides by 3 to get
x=7
Then, we just plug x into 10x-3 to get BD = 7*10-3 = 67
Answer:
The answer to your question is below
Step-by-step explanation:
Each square values two units
I hope it helps you.
Answer:
4/5 24/30
Step-by-step explanation:
Answer:
<h2>
46</h2>
Step-by-step explanation:
x - age of a son three years ago
3x - age of a father three years ago
x + 3 - age of the son now
3x + 3 - age of the father now
x + 3 + 5 - age of the son in five years time
3x + 3 + 5 - age of the father in five years time
in five years time, the father will be twice as old as his son, so:
3x + 3 + 5 = 2(x + 3 + 5)
3x + 8 = 2x + 16
3x - 2x = 16 - 8
x = 8
x + 3 + 4 - age of the son in four years time
8 + 3 + 4 = 15
3x + 3 + 4 - age of the father in four years time
3×8 + 3 + 4 = 31
the sum of their ages in four years time:
15 + 31 = 46
