$$4-9+8+9+2$$

$$\left(-2+7\right)\cdot\left(-3-1\right)$$

$$\left(x\:\:mas\:3\right)\:\left(x\:mas\:7\right)$$

$$\left(-8x+4\right)\left(7x-3\right)$$

$$\left(e^x+1\right)dy=\:\left(y-ye^x\right)dx$$

$$\lim_{x\to-2}\left(\frac{\left(h-5\right)^2}{h}\right)$$

$$-\left(7g+5.3\right)$$