Answer:
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.
Then you are able to substitute in X and it can have a infinite number of values catered to the question.
Answer: m∠QPR = 40
<h2>
Step-by-step explanation:</h2>
Because PG is perpendicular to PS, it is safe to assume that angle QPS is 90 degrees.
(7x-9) + (4x +22) = 90
x = 7
Because we need to find the degrees of QPR, plug in the equation for that angle with the value of x we found.
7(7) - 9 = 40
m∠QPR = 40
