Question 697114
{{{9(a+1)^2-4(a-1)^2}}}


{{{9(a^2+2a+1)-4(a^2-2a+1)}}}


{{{9a^2+18a+9-4a^2+8a-4}}}


{{{5a^2+26a+5}}}


So {{{9(a+1)^2-4(a-1)^2}}} simplifies to {{{5a^2+26a+5}}}