Ah, yes
if you start with P amount of something and the half life is h units (in years) and the time elapsed is t (in years) then the amount left is A
the equation is

so
given
h=1620
P=150
t=200
so


use your calculator
A≈137.69781917515g
about 138grams left
Area of circle 1 = πr²
Area of circle 1 = π (10)²
Area of circle 1 = 100π km²
Area of circle 2 = πr²
Area of circle 2 = π (5)²
Area of circle 2 = 25π km²
Number of times the bigger circle is greater than the smaller circle

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Answer: The big circle is 4 times greater than the small circle.------------------------------------------------------------------------------------
Y=-x+b
plug in x = 4 and y = 1 to find b
1 = -4 + b and we know that if you add 5 and -4 you get 1. So ...
5 = b so if we plug that in
y= -x + 5
which is the same as y + x = 5, So it would be A
Answer:
-9
Step-by-step explanation: