Question 936216
log (k+2) + log (k-1) = 1       log 10 =1

log (k+2) + log (k-1) = log 10
 formula :  log a+log b  = log(a*b)
   log (k+2)*(k-1)=log 10
       (k+2)(k-1)=10
        k(k-1)+2(k-1)=10
           {{{ k^2+k*(-1)+2*k+2*(-1)  =10}}}
         {{{ k^2-k+2k-2 =10}}}
        {{{ k^2+k-2=10}}}
           move 10 to the left
 {{{ k^2+k-2-10=0}}}
      {{{ k^2+k-12=0}}}
*[invoke quadratic "k", 1, 1, -12]