Question 74838
Let x equal the number of rows of the original grid. Let y equal the number of characters.


{{{y=x^2+24}}}and {{{y=(x+1)^2-25}}} so {{{x^2+24=(x+1)^2-25}}}


{{{x^2+24=x^2+2x+1-25}}}


subtracting {{{x^2}}} from both sides and adding 24 to both sides gives 48=2x or x=24.  This means y=600


I'm not sure about the quadratic equation that you need but this solution does use a second order equation