Answer:
y= 7^-t
Step-by-step explanation:
Equation for exponential decay:
An equation represents exponential decay if a term between 0 and 1 is elevated to the independent variable.
In this question:
First option 4 is elevated, so not exponential decay.
Second option:
, thus, the second option represents exponential decay.
The given equation is
And we have to solve for y.
Solving for y, means isolating y . And to isolate y, we need to get rid of 4 that is with y .
It means we have to separate 4 from y, and for separation , we have to perform division. That is, we have to divide both sides by 4, and that will be the next step .
So out of the four options, correct option is the last option .