# Math Help - Exponential Growth & Decay

1. ## Exponential Growth & Decay

I'm not sure how to go about finding the solution, so any help will be much appreciated:

q'=0.14q
q(0)=-5
q(x)=?
q(7)=?

2. Originally Posted by blurain
I'm not sure how to go about finding the solution, so any help will be much appreciated:

q'=0.14q
q(0)=-5
q(x)=?
q(7)=?
$q' = 0.14q$

$\Rightarrow \frac {q'}q = 0.14$

$\Rightarrow \ln q = 0.14x + C$

$\Rightarrow q(x) = Ae^{0.14x}$

now use your initial data (that is, q(0) = -5) to solve for A. then you can answer the rest