$$\tan\left(x\right)\sin\left(x\right)-4\tan\left(x\right)=-3\tan\left(x\right)$$

$$ad-3cd+ca-a+3b-3bd$$

$$1+6-11-84+28+240$$

$$\int k\cdot\left(4-x\right)dx$$

$$7\left(z+5\right)$$

$$\lim_{x\to\frac{\pi}{2}}\left(\frac{tanx}{\frac{18}{2x-\pi}}\right)$$

$$2087\:-\:1359$$