Answer:
x=6
Step-by-step explanation:
I would look at this triangle and notice that x can be solved by setting up a ratio.
I generally put the short side of the triangle on the top and the long side on the bottom
4/x = x/9
You then cross multiply to get 36=x^2, or +-6=x
A length of a triangle cannot be negative, so we are left with the answer x=6
Answer:
Solve 3-6x >= 0
6x <= 3
x <= 1/2
Domain: All Real Numbers <= 1/2
The amount of substance left of a radioactive element of half life,

after a time, t, is given by:

Given that <span>potassium-40 has a half life of approximately 1.25 billion
years.
The number of years it will take for 0.1% of potassium-40 to remain is obtained as follows:

Therefore, </span><span>the maximum age of a fossil that we could date using 40k is
12.5 billion years.</span>