<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>
12 to the second power is equal to 144
(12 x 12)
Answer:
because 25/100 = 1/4
0.20 = 20/100
Step-by-step explanation:
because 25/100 = 1/4
0.20 = 20/100
because 0.20 means 20 tenths 0.23 > 1/2
because 0.23 = 23
0.4 = 1/4
because they are on the same place on a number lin
Answer:
the answer is -7
please mark this as brainliest
97 rounds up to 100
78 rounds up to 80
100x80= 8,000
estimate=8,000
97x78=7,566
product=7,566
