$$\left(6x+2y+7z\right)^2$$

$$\int_4^9\frac{\left(\sqrt{x}+3\right)^2}{\sqrt{x}}dx$$

$$\int\frac{4s}{\left(1-2s^2\right)^2}ds$$

$$\int\left(\frac{e^{4x}}{e^{4x}+7}\right)dx$$

$$149\le26s+45$$

$$\cos^2x-\sec^2x$$