Answer:
[tex]t=-5ln\frac{7}{3}[/tex]
Step-by-step explanation:
[tex]300e^{- 0.2t}= 700[/tex]
Divide both sides by 300
[tex]e^{-0.2t}=\frac{700}{300}[/tex]
[tex]e^{-0.2t}=\frac{7}{3}[/tex]
take ln on both sides
[tex]ln e^{-0.2t}=ln \frac{7}{3}[/tex]
[tex]-0.2t ln e=ln\frac{7}{3}[/tex]
[tex]-0.2t=ln\frac{7}{3}[/tex]
divide both sides by =0.2
[tex]t=-5ln\frac{7}{3}[/tex]
