Find t given:
$$0.715+258.115e^{-0.5t}-67.83e^{-0.25t}=0$$
Please help. I've substituted $e^{-0.5t}$ for $x$ and did
$$-67.83x^2+258.115x+0.715=0$$
but the answer is not coming out? Am I doing something wrong because it doesn't follow the quadratic rule?
If you let $e^{-0.25t} = k$
The equation then becomes:
$$258.115k^2-67.83k + 0.715 = 0$$
You should be able to solve the above quadratic equation and then find the values of t by solving $e^{-0.25t} = k$.