<span>60.5 milligrams per square centimeter
First, determine how many half lives have expired by dividing the time by the half-life. So:
55/20 = 2.75
That means that only 2^(-2.75) = 0.148650889 = 14.8650889% of the original substance remains. So just divide the amount remaining by 0.148650889 to get the original amount.
9 / 0.148650889 = 60.5445419
So originally, there was 60.5 milligrams per square centimeter 55 years ago.</span>
Answer:
-2.167
Step-by-step explanation:
6X = 2-15
6X = -13
X= -13 / 6
I cant see one of the numbers
Answer:
70
Step-by-step explanation:
2 + 10 = 12
84 ÷ 12 = 7
7 x 10 = 70
She graded 70 maths papers and 14 science papers.
Answer:
<h2>x=29</h2>
Step-by-step explanation:
<h3>to understand the solving steps</h3><h3>you need to know about:</h3>
- right angle
- equation
- PEMDAS
<h3>to solve:</h3><h3>x</h3><h3>let's solve:</h3>
<u>a </u><u>right</u><u> angle</u><u> </u><u>contains </u><u>9</u><u>0</u><u>°</u> (always)
according to the question
x+3+x-1+x+1=90
3x3=90
x=87
x=29
<h2>solved</h2>