## College Algebra 7th Edition

$(a-1)(a+1)(a-2)(a+2)$
Think of the equation as $x^{2}-7x+10$, with $a^{2}+1$ being $x$. We then get: $(a^{2}+1)^{2}-7(a^{2}+1)+10=[(a^{2}+1)-2][(a^{2}+1)-5]=(a^{2}-1)(a^{2}-4)=(a-1)(a+1)(a-2)(a+2)$