Question

PLEASE HELP!! ANSWER TODAY!!! The half life of a certain substance is about 4 hours.the graphs shows the decay of a 50 gram sample of the substance that is measured every hour for 9 hours .Which function can be used to determine the approximate number of grams of the sample remaining after T hours

Answer 1

it's D or y = 50(0.85)t

Explanation:

Answer 2

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.


`y = a(b)^(x)`

`26 = 50(b)^(4)` (divide both sides by 50)

`0.52 = b^(4)` (isolate B using the properties of exponents)

`b = 0.52^{ (1)/(4) }`

`b = 0.849182...`
This can be rounded to 0.85.

So therefore, the function that represents the half-life decay is
`y = 50(0.85)^(x)`.