If a-b=0.9 and ab=0.36 find, (i) a + b and (ii) a^2-b^2
1 answer:
You might be interested in
The answer is 74,000 years.
It can be calculated using the equation:
<span><span>
<span>
<span>
<span>
<span>
<span>
<span>
<span>
<span>
<span>
<span>
<span>
<span>
<span>
</span></span></span></span></span></span></span></span></span></span></span></span>
<span>
</span></span></span><span>
</span></span> = decimal
amount remaining, where n is a number of half-lives.
<span>Decimal amount remaining is 0.00012 (= 0.012%). Let's calculate number of half-lives.</span>
<span>
</span>
⇒
⇒
⇒ n ≈ 13
<span>
Now we know that number of half-lives is 13.</span>
Number of half-lives is quotient of total time elapsed and length of
half-life.<span>
<span>So, total time elapsed is a product of length of
half-life (5,730 years) and number of half-lives (13). Since 5,730 years × 13 =
74,490 years, then the person died 74,000 years ago (rounded to the nearest thousand).</span></span>