Question 966028
This, A=A0eKT, does not mean what you want it to mean.


THIS means what you want, using pure text:  A=A[0]e^(KT)


Inside the rendering tags, you find  {{{A=A[0]e^(KT)}}}.


Now to solve for K,  take logarithms of the left and right sides, and then substitute appropriate values:


{{{ln(A)=ln(A[0])-KT*ln(e)}}}


{{{ln(A)-ln(A[0])=-KT*1}}}


{{{KT=ln(A[0])-ln(A)}}}


{{{K=(ln(A[0])-ln(A))/T}}}


{{{highlight_green(K=ln(A[0]/A)/T)}}}


Then substitution,
.
.
{{{highlight(K=ln(2)/7)}}}