$$[\left(-8\right)+5\cdot2-4:\left(-2\right)]\cdot\left(-7\right)$$

$$\int\frac{x^2}{\left(4x^2-4x-3\right)^{\frac{3}{2}}}dx$$

$$\sqrt[3]{8x^3}$$

$$sen^2sec^2+sen^2csc^2=sec^2$$

$$\left(-2\right)\left(9\right)$$

$$3a^2b-3a^2b$$