Based on the calculations, the unknown number is equal to 
- Let the unknown number be x.
<h3>How to find an
unknown number:</h3>
Translate the word problem into an algebraic expression, we have;
Adding 21 to the unknown number:
Multiplying the result by 3:
84 more than two-thirds of the unknown number:
Equating the equations, we have:
Cross-multiplying, we have:
Read more on word problems here: brainly.com/question/13170908
Half-life = [elapsed time * log (2)] / [log (begng amt / endg amt)]
half-life = (3 days * 0.30102999566) / log (1 / .58)
<span>half-life = 0.903089987 / log </span>
(<span>
<span>
<span>
1.724137931)
</span></span></span>half-life = <span>0.903089987 / 0.23657200643</span>
half-life =
<span>
<span>
<span>
3.8174 days
Source:
http://www.1728.org/halflife.htm
</span></span></span>
The answer is 40.4
When you take a percent of the number you make that percent into the hundreds place. For example 40% of 101, you would do .40 x 101 to get 40.4
Answer:
b
(-1,-7
Step-by-step explanation:
