$\left(\frac{3}{5}a+1\right)\left(\frac{3}{5}a-1\right)$

$\lim_{x\to-\infty}\left(\frac{\left(2x\right)}{\left(x^2-4x+3\right)}\right)$

$\int\frac{240\:}{t^3+2t^2-15t}dt$

$x^{2}+18\times81$

$225^2-169^2+1+30+26$

$\left(a^3+b^3\right)\frac{2}{3}$

$x^2+2\left(x-1\right)+3x\left(x^2+1\right)+5$