$$-20-5+4-\left(-1\right)$$

$$\left(-24\right):\left(-6\right)-2\left[8:\left(-4\right)-\left(-2-3\right)\right]-1$$

$$\int\sin^2\left(zheta\right)\cos\left(zheta\right)d\left(zheta\right)$$

$$36.07-5.01$$

$$\left(2x+5\right)\left(x^2-9\right)$$

$$\left(\sqrt{2}+\sqrt{3}i\right)\cdot\left(\sqrt{3}+\sqrt{3}i\right)$$