Hello.
So you are given the initial amount (50 grams) and two other points on the graph, (1, 42.5) and (4, 26).
Let's find the exponential function.
[tex]y = a(b)^{x}[/tex]
[tex]26 = 50(b)^{4} [/tex] (divide both sides by 50)
[tex]0.52 = b^{4}[/tex] (isolate B using the properties of exponents)
[tex]b = 0.52^{ \frac{1}{4} }
[/tex]
[tex]b = 0.849182...[/tex]
This can be rounded to 0.85.
So therefore, the function that represents the half-life decay is [tex]y = 50(0.85)^{x} [/tex].
