$\sqrt{7a}7$

$\left(4x^2\:+\:y^2\right)dx\:+\:xydy\:=\:0$

$\lim_{x\to0}\left(\frac{y\left(x-7\right)}{\left(x-7\right)^2+3y^2}\right)$

$\int\left(\frac{0.06t^2}{6+0.02t^3}\right)dx$

$\frac{64a^6-4b^{12}}{8a^3-2b^6}$

$15\:+\:\left(6\:-\:18\:+\:11\right)\:-\:\left(7\:+\:15\:-\:19\right)\:+\:\left(1\:-\:3\:-\:6\right)$

$5\sec\left(2x\right)+7=0$