$30\:-\:20\::\:\left(5\:+\:15\right)$

$\int_4^{\infty}\left(-\frac{1}{x^2+3}\right)dx$

$\csc\left(x\right)+\cot\left(x\right)+\frac{\sin\left(x\right)}{1+\cos\left(x\right)}=\frac{2}{\sin\left(x\right)}$

$y''-9y=0$

$a\:=\:110^{\circ},\:c\:=\:30^{\circ},\:c\:=\:3\:2$

$\int\left(4x^3-3\right)\:\ln\left(x\right)dx$

$\frac{d}{dx}+2y=e^{2x}$